I made this post in the general discussions but since it is somewhat an overview, halfbaked guide, I will post it here as well.
This assumes max upgraded skills, obviously. Simply because looking at something without the full capabilities of the class seems rather pointless. Here goes:
Tecs are very versatile, slippery and can spam ranged AOEs to no end and due to their insane spam of their skill-version of faith, that breaks them out of literally everything, including paralyze and sog, has a 17 sec CD (argent glyph is must have here) and can stack upto 3 times...you can literally not CC them if its you alone vs one of them. They will get away. Their damage is also a bit higher than archers and even other caster, heck you could say they are basically a mostly physical caster with LA-Armor, just because they have both a range AOE physical debuff (50%) and a ranged AOE fire debuff (60%), so even on the damage front they are highly versatile. Then there is the skill that insta-kills ppl when the HP drops below 22% (I always assume lv5 glyphs for average values) which is extremely good vs nasty, endgame geared ppl that barely survive an onslaught.
Due to the fire debuff they are also capable of performing the same level of "fire-combo" as wizards do, which is extremely good and works even better than for wizards, due to the simple fact that they don't need to use their genie for as much as other classes do, simply because they have their genie-like faith skill that can be used just as genie skill can be used, any time, without any means of stopping it, unlike genie that can be blocked by mystics. Hence they can get away with sporting dex based genie, even more so since they can abuse the fact that expel lasts longer with more dex there and insta-faith out of it literally every time, which makes them very competitive to duskblades and Sins alike in a direct confrontation. That's just the tip of the iceberg tho. They also have a 25m jump skill that grants them 2 sec of immunity to movement debuffs (just stun, freeze) and also stacks 3x times (here I recommend the argent glyph as well, green increases crit damage but imho..30% more crit damage is just not worth having to use the jump before that every time, renders you less versatile and also forces you to use verdant glyphs on the attack skills which you should NOT do). They are slippery as all hell and will be a pain to be dealt with in 1v1 and Mass pvp scenarios if the class is mastered. Just remember, they can use a better version of faith every 17 seconds..so dont bother SoG'ing them or trying long CCs on them, they break out anyways. If you wanna kill them, kill them with pure damage. Some debuffs like PT cannot be faith'ed off, so make use of that, same goes for rend.
On the Damage side, Tecs are also not to be underestimated. I highly recommend using a full argent glyph setup for mass pvp, with the one exception being the red glyph on the "insta kill when hp is lower than 22% HP" skill, for obvious reasons. The way argent makes the skills stack is that their 3rd and 2nd CDs instantly start to fill again after you use it, so if you have a decent rotation, you never run out of AOEs to spam. Argent on Expel allows you to keep the phys debuff up permanently, since it makes the skill stack up twice. Same should be done for Murderous Indulgence, you main damage skill. 460% Base damage is quite massive to begin with but the kicker is more the knockback that comes with it and can be quite nasty in it's own right. If you are within 10m of the target they get knocked back and the flight lasts for roughly 1.5s, so basically a 1.5s CC and with the argent glyph it stacks twice. All CC you can get you should get ijs. The Argent glyph on Neon landing could also be great. It paralyzes an entire group of ppl for roughly 1.5 seconds and can be stacked twice due to the argent effect as well, literally allowing you to spam it twice in a row. Remember tho, that skill costs 2 sparks, so you better have your paramount ready, or full chi and use another aoe in between but then you are dry on chi. Can be great depending on the situation..with enough focus..even 1.5 seconds of CC can get ppl killed big time. You can also use the argent glyph on flow, your only spamable real AOE as expel and tide of flame are frontal AOEs. It stacks twice and deals good damage and does also recover a good bit of Chi, which should always be considered. Ofc, all of those skill are also hella fast, which rebuilds chi just as fast hence why going full argent for the most skills is the Top-Choice for PvP and PvE. Since Tecs have a fire debuff..depending on your gameplay/situation you can also use the red glyph on flow and expel, when you simply dont need the physical debuff from expel itself. It removes that, but converts those 2 skills into fire damage. Fire combo much? Being able to abuse veno/sb ulti with elemental damage or just abuse elemental weak enemies is awesome, or just add your own spark (genie skill) into the mix for some juicy oneshots. Silent Mayhem could also be used with the argent glyph but remember, it has a long CD (30 secs each stack) but can be insta-cast and gives quick 30 chi per use. So if you find yourself in a 1v1 where quick chi matters, you might wanna consider this but otherwise the skill really is just too slow and has a too long CD to be considered. The regular skill can be used for some juicy charmbypasses, so thats already quite good.
As for the traps. They are nice. Not bad at all. They require you to basically be in someone face to make them count but for 1v1 situations or small scale PvP that is not that much of a problem, since you can leap in and out without ever being stopped due to your spammable faith-like skill if you really need to land your CC trap or Amp trap. The destealth trap kinda surprised me. It's friggin amazing. It kicks out everything from stealth, disregarding their stealth-level whatsoever, as long as they are in range. Even sins in ulti are somewhat permanently attackable if they stay in there. Finally a half-decent counter to sins ulti. Not perfect, but good enough. The knock-back trap is also roughly a 1-1.5s CC and can be nice in tricky situations. Remember, melee classes do still have to jump/walk up to you to attack, so that is not bad at all.
Lastly, we have the turret skill and the one aoe you can use while transformed. You cant use genie skills..so I literally would only use this if you used an immune pot before and dont need to add your own debuffs/CC into the mix and just wanna dish out damage. The damage is good. Very good. Tho it is a bit on the random side in terms of how hard it hits. Sometimes it seems like it would stack with every attack but then it gets lower again. It's tricky and I definitively need to test this more but the use-cases are limited anyways, so it is not that important. It's physical damage, btw. Tec also have a skill that kicks a squad member away for 25m? 20m? something like that, cannot check atm, and renders them immune while they are flying in a rather beautiful arc. Ofc, you can make this the ultimate troll skill and annoy the heck out of your team but honestly, if you have a good overview over the battle..you can save ppl with that big time. Anyone knows the feeling when a horde of barbs, bms, duskblades and sins jumps on you can you cant move an inch due to perma paralyze! BOOM! you are 25m away now and might be able to escape! Has it's use, no doubt about that.
That's the basic of the Tec class, there is a bit more to it, as there is always more to pay attention to when it comes to detail, like which specific genie built to use for which PvP/PvE situation, vs which classs/classes and so on, like the preference for both new classes to use STR based Occult Ice/Mire genies vs Arcanes to mitigate the lack of CC and Dex based genies for spark/fire combos vs HA/LA (especially since the elemental skills are 100% accurate and do not miss).
PS: I prefer Demon for the Tec. Trip Sparks Crit addon makes all hits 100% crit on a semi-endgame gear setup which is great, increases the AMP to 20% (from 15%) and increases the CC-Traps Stun to 4 seconds (from 3) and makes the regular spam skill slightly faster, which allows for more chances of sneaky charmbypasses. Tecs are weird in that regard. Since all their skills have nearly no chan at all..sometimes the server skips one animation, casts the skill anyways and counts 2 or even 3 skills together as if they were used at once. Crazy and weird but its fun
Sage on the other hand basically has the basic chi skill Master Li's, Damage reduction from trip spark and a 25% chance to regain 20 chi on the regular spam skill..which is RNG and isnt used often anyways. The other AOEs also produce loads of chi hence I think sage is rather pointless for a Tec. It's a DD class after all, so even the trip spark is better for that purpose but to each their own!
PSS: Some skills are kinda quirky. Meaning that, if a target has just appeared (mostly happens in PvE) some skills will just go into the void and are effectless if you use them instantly. I cannot tell if the same thing applies to freshly spawed enemies, like with porters in xTW but I would assume so. Hence, always wait a second before you attack someone that has just spawned or just use the regular spam skill first. That one seems to always work. Mainly Expel, flow and Tide or AOEs in general seem to be effected by that.