Large Guns: Explain more, please. If I wanted something like a sniper rifle, I'd probably use something in the Magnus line of guns. If you have something else in mind, do tell.

Hammer Time: See this thread. You might wish to discuss a hammer there.

"the tank shield from LD to be an actual shield for arcade": Why not go all the way and include all LD classes? See my thread on Class Missions and tell me what you think.

Support Wands: Would these be any different from vaporizers and alchemers?

Poison: Poison already slightly lowers enemies' defense. I've actually been thinking of getting a toxic vaporizer because of the added damage. Personally I don't see much reason for poison to go so far as to modify damage resistance/weakness, since those modification would have too much of an impact on the amount of damage dealt.