Two of the most requested items in dust at the moment that aren't "balance stuff, damnit!"

So, here's my two cents on how this could work.

PVE could be used to unlock modifiable weapons. Mercs get contracted to fight priates, drones, other things. These enemies don't use standard issue weapons, so through fighting them, you unlock research credits or somesuch or isk(another currency grind, ugghh, I know) which can be used to manufacture modified weapons. Basically a choice between selling off the various salvage or keeping it to disassemble yourself.

Modified weapons have to be purchased as a base model(regular market, isk), and the modifications themselves are considered blueprints, changing them costs research credits, unlocking them costs research credits, but once you have a configuration you like, you just need to purchase the base weapon.

Better mods/versions of mods can only be unlocked by completing higher tier(more difficult) missions, as well as increasing in cost to manufacture and swap. for example, the starter tier suppressor quiets your shot, the highest tier one removes the "you've been shot notification"(red semi-circle thing) from the enemies hud. making it costs 5 missions, swapping it afterwards only costs one. the higher tier one takes at least 1 highest tier mission completion and salvage option taken to unlock research, and takes 10 high tier completions to manufacture and one high tier to swap.

Modified weapons have their own skills, but they only effect the efficacy of the modifications themselves.

as for the modifications themselves, I was thinking of the "standard" kinds of modifications present in other games.

Barrels: Modifies range, upward recoil, sound/flash suppression
Stocks:Modifies sway recoil, weapon swap speed, melee damage
Ammunition:Modifies damage spread(not switching shields/armor, but tweaking a few percentage in either direction) and range
Magazine:Modifies ammo count and reload times
Optics:It's a sight. affects zoom.
Underslung:Laser sight to reduce spread, Flashlight to see cloaks at 10 meters or less, Target painter to pass intel to your team while you have them sighted, it's your utility slot. Can also mount a weapon system, but this makes the weapon take up your secondary slot as well.

anyone have anything to add? this seem like a bad idea? good idea?

would be kool to finally see some PVE there is so many idea's for the missions they can do it actually endless but would like to see some big scary alien most like http://www.deviantart.com/art/The-Rah-Yeran-left-side-382563091 running around trying to kill everyone, or maybe during PVP there could be hostile enviroments like acid rain or man eating plant or mosters randomly running around the map