Human weapons are less effective against shields, so a problem there. I would advise you just use triggers.
Comments?
I bet your map won't own as much as mine will.

Mine won't be Halo-themed(though, I got the inspiration from an idea I thought of that would work quite well for a Halo map), but it will be pretty awesome if I finish it, and if I don't I'll make a demo-map which will show-off my 1337 ideas.
Only thing I can say is that the map would hard to make correct aestheticaly, and it'll probably be hard as Hell to balance.