I do not know about the door lock situation, but I have put an alarm in my 92 yj. I put a viper 600 with a prox censor. What the prox censor does is it warns away any movement. You can set this up to 6 feet around the vehicle. I do not know why you would want the alarm set that censitive, but it is possible. It works off of two zones the inner zone which is the inside of the vehicle and then the outer zone which is the outside of the vehicle. You have to adjust the prox for the right setting so that when the wind blows it doesn't go off.
For large items such as doors an alarm would be useful. People can always reach in and take things quickly. The alarm doesn't totally protect you, but it does to a certain extent.
hope this information is useful
92 yj, 2" body lift, 1" shackle,
2 1/2" Old Man Emu suspension lift, 31' All-terrain BFG's