Security Abuse

[BlackPhoenix]

Pushing people down isn't assault, however doing it while they're trying to get a traitor, i can safely say. Generally i'd say that pushing down security - or anyone else for that matter - is more of a friendly tease, than assault. Also brigging someone for "borrowing" a space suit seems overkill, let the damn man have some fun!
If you personally think they're being annoying with the disarming, tell them. They are most likely doing it because they're bored or something, give them something to do, and they'll likely leave you alone.
Or if you're feeling especially robust, try challenging them to a push-down fight, if you win they stop, and if they win, they get a pair of sunglasses. Make it fun for everyone, instead of being negative about it.

Stealing three space suits is a bit excessive.

Honestly, just ask why he wants them. The odds are, the dude wants to get to an abandoned station with some buddies. Stun him, cuff him, then start talking to him. Be ready to release him and apologize for the formalities if he's not being shitty.