1) Run more electrical outlets, looks like you have (1) 2 port outlet...Id have a couple on each wall, if you get a work bench youll need a couple, youll also probably run de-humidifies, lamps , etc etc etc.
2) I probably wouldnt dry wall, itll eat up space, unless you need to run insulation behind it. If you skip the dry wall, id paint / seal the concrete.
3) Id look into some rubber backed carpet for the flooring.
4) put some kinda ceiling up, exposed insulation looks like crap.
5) More lighting, and I would go with all LEDs. You can get 2-3 foot shop lamps that are LED.
6) Id have multi workbench stations, one clean assembly area, and one dirty / cleaning area.
7) small table top parts washer.
8) Gun rack to stand guns up while working on them.
9) Built in gun vice..with adjustable forehand area to accommodate various length firearms
Jus curious, why the odd shaped room? I think i wouldve squared it off.