There is two question-suggestions:
1-st) can I somehow change wrench's building menu (make it custom or add new pages or implement images)?
if not - do it pls

2-nd) can I somehow make custom buildings using construction zone(building 10) which uses cs2d's pattern?(would be good to have it's source code or at least implement ability to add custom breakable objects to make more constructions).

as far as I know there is no possible ways to make custom breakable with specific command, except using image and imagehitzone, but compare to cs2d's built-in BUILDINGS which might work easily with the way cs2d-editor do it (env_breakable) and ability to use built-in BREAKING/DAMAGING buildings with correct HP show, without making lua for it to get HP output(not to use mousemapx/mapy and in case of worse ping or connection problem u see delay of all actions). Makin WALL III and place image over it for example custom turret(rocket launcher or whatsoever) would not look like (Rocket turret made by Mora) but like (Wall III by Mora). not good tho