about weapons:
you can patch them to the server, so you wont be banned, but note: if the server doesn't see the weapons, the players doesn't see it to, so the weapon become useless.
about entering a locked vehicle is easy:
NOP SetPlayerPos (necessary in some cases)
NOP SetVehiclePosition (necessary in some cases)
NOP SetVehicleVelocity (necessary in some cases)
NOP RemovePlayerFromVehicle
NOP SetEngineState
press "Home"(yes the key on your keyboard called Home), when your near the vehicle
and done!
i used to do this alot at samp 0.3b... good times..