Phenixtri has written
NPCs need a little work for the sake of mods & making CS2D more dynamic in terms of game play & mods, both of which make up a large part of the fan base. A weapon customize option isn't really a good idea in my opinion, keep in mind that CS2D is based off of CS1.6 so thus only weapons, features, & NPCs from CS1.6 to CS 1.0 & HL1 (since CS was originally modified from it) are recommended.
The ability to customize the existing CS2D weapons via some kind of server / client side secure script (similar to source or lua) would only be useful for mods & mod servers. Basically being able to change the guns names, ammo per mag/reserve, maybe ammo type, to secondary ability's (like silencers & 2x / 4x scopes), rate of fire (limited to 1,200 rpm to eliminate lag issues & that's all that's really needed since the fastest normal MG fires around that rate).
But again this would only be useful for mods & thus is not really a high priority.
Also on another personal note I would like to add that individual scope sprites for the Sig. 552, AUG, Scout, AWP, Sig. 550, & G3.SG-1 would be be great for the sake of both skin makers & moders. DC can just reuse the default CS2D scope but just add specific names for each sniper rifle scope (total just 6). The CS2F community can make customized scopes for it on our own & it would make the game a bit more dynamic for customization.