G17 Weapon: which?

Axes
Because thats your main skillset... I hope...

So the big thing you should ask right now is, are you pushing for it as your main weapon or is it going to be a support sidearm? If it's going to be your main weapon and you want it at 5th cast definitely go with axes, that's the generally best skill set for PvP, especially with the highest stun times.

If you're planning on using it as a utility sidearm then I'd say axes or swords are best.

Axes would be best if you had Spirit Blackhole or Heartbite Rend for PvP support purposes and with the G17 Spirit Blackhole being able to go off with other skill debuffs it means you can maintain stunlock easily while using it since you don't have to mainly auto-attack to set off its purge effect.

Swords are also good as a support sidearm because as you said great chi building and it means you're not packing 2 sets of axes around because it does feel very redundant. I can't think of much good to them aside from some skills with the highest damage to them, even if its not the highest damage weapon. Could definitely be an effective offensive weapon if used carefully.

Poleblade is one that I would say could contend for offensive purposes given the addition of base weapon range and an extra ranged attack with a freeze to catch running targets and if you're willing to sacrifice paralyze time you can get extra range on Dragon Rising to catch running targets. I mainly feel its debuffs and other skill effects are very lackluster compared to axes and it would be best as a support sidearm with offense potential. For offense though it would take a great amount of skill to use effectively over axes.

Fists in our games current meta are definitely best used for PvE or support sidearm. No doubt if you wanted to go through the expensive and long process of making a very OP APS set that could survive in PvP it could be a very good option, but that's a lot of rerolling and hoping that RNGesus blesses you with the stats you need. In the end it would be better just to get R9R3 and not try to APS in today's PvP setting.