what gem on my NP?

I say go Citrine gem or
make it 2 socket and take one of each: end of the story
more seriously for the taming its bad reason: just use those apothecary pots or use a noob cleric to RB if you want

Im a cheap veno so i went mag attack: more channeling means more mp loss over time

b:embarrass i use cleric as MP pots but if i go channeling ill abuse clerics
b:chuckle SleepCat is even worse than me *epic Soul Transfuse*

and again it depends on what you want: if its only 1 shard 3% channeling wont really matter over 300 magic attack

its good to have some channeling but in the end the cooldown doesnt go down unlike interval for melee that amplify the effect.

For me I use channeling mostly for boss or pve and in that case i use channeling gear.
3% channeling

with weapon you have -22% if you add -3% its goes to -25%:

Math time
Venomous
Cast 1s
Channel 1.5

so
22%=1+(1.5-22%*1.5)=2.17
25%=1+(1.5-25%*1.5)=2.125

woot so 0.045 faster

Some over time info
Cool down 1 sec
To attack 10 times same skill
22 => 30,7 sec
25 => 30,25 sec

Those number to be honest is mostly for heal pet unless youre stupid enough to spam same skill over and over and be limited by that cooldown all the time.

BTW my math is messy so im open to a reply to this that will say im wrong

PS: i didnt do math for attack difference btw no gem and gem cause im lazzy and formula is a little more tricky to calculate
PS2: Exception in duel against same class channeling will give you the first stun/seal... so you can win because of that but in open pvp i dont really know the difference of 3% channelling