Sure i can..
Stealing cost energy, that is the "cooldown".
You can steal money or stuff.
Stuff can be protected in a special bag.
Money can be protected in a bank (also items in limited amount).
Characters don't disapear when you are "off", so, you can search a character in his bed and steal him ...
You can also steal a on-line character of course, because you can be sneaked to the equivalent to one hexe (that do think me, that can be a good idea to allow sneak less to 3 hexe with a steal boy) skills are really more important than in Fonline. With a very good perception skill it's hell to steal you.
Cops are players, so you can ask for research a stealer and your stuff (stuff is numeroted and traceable but don't except too ^^)
I was a stealer in this french game and it was my main activity. A very lucrative activity if you have friends and be organised.
First, bags. Limited for carry, steal it is harsher because bags are heavy with the stuff inside.
2 Craft improved bags locked? and trapped?
3 banks do interests again. Peoples go to bank them caps. Stealers see for robe it at this moment!
4 allow to steal (snatch) an object in a hand with a strenght roll, but ... character know you are a stealer and all can shoot you if you do that!
5 GM can allow few players to manage reputation of towns (and so, guards). -300 no protection with guards. -Xk shoot in sight by the guards. Die don't cancel that ... only time. They can also improve reputation and play rangers sheriffs
or VC sheriff or hub ^^
6 Idk exactly stealing mechanics but ... with a motion sensor, it's hard to steal someone? If no, revise influence of perception on stealing or give special bonus anti-steal to motion sensor.
7 when barting, you can't quit if you don't make the deal or take back all what you was proposing to bart. Imagine you show all your stuff to the barter, you can't just say "bye bye" and run ... or the stuff keep on the floor!
(my main activity is barting, so ..)
8 add quests in town. Rewards of quests are goods spot for steal. Maybe a quest of stealer?
9 Add more little stuffs in png in all towns like in the den with beers, stimpacks, booze, ammo, some weapons etc but that must be attractive, not too shity stuff. For xp and farming => more little pvp circonstance if someone see you.
10 mercs/slaves/companons shoot automaticly a stealer if he lose his roll.
In my past experience of stealing in Fonline, i has some goods moment. Not at NCR. I stealed more than 20k caps, and few good stuff... but it's not enought lucrative for be a main activity ... except stealing Enclave but i find it's just boring.