1987 fiero gt manual remote start

Ok, as cool as this idea is, I think we're going to abandon it. The car will be sold after this is done and I dont want it to fail and kill someone. The pin switches would be depressed every time the car shifts gears (hundreds of times per day perhaps), which might wear out the switches and cause them to malfunction. I would do it if the e-brake could be used as a failsafe but these cars have very bad e-brakes that are very hard to keep in working condition.

So.... we're going to wire it to work like a normal manual remote start (kind of). It'll have push button start and a seperate switch for accessories. If accessories are switched off and car is left running, then door is opened and closed it will arm the alarm and connect the starter to the remote start. If the car is shut off before the door latches, or the door is opened twice, then remote start is disconnected from the starter. This way the only way it can be started in gear is if someone sets it, then reaches through the window and puts it in gear. So now, my questions:

1) This is the way many systems on the market work, right? Do they have any failsafes, like the ebrake, or do they assume someone wont exit through the window while leaving it in gear?

2) I'd ilke to "set a flag" that says its ok to start remotely by holding a charge in a capacitor. Any problems with that? How long will it hold a charge?

3) I want to arm the alarm automatically when the door is shut. We dont have the alarm yet. What alarms out there allow you to do this? I want to be able to send a pulse to the alarm that makes it arm.