yeah pressing 2 buttons all the time would be a major piss off me thinks. Pressing one is hard enuff, haha
as for the someone getting in a opening the boot, well my car was broken into out the front of my house not so long ago (window was down slightly, as the power window cable snapped, so window was held up by bambo stick, anyhow) all they stole was my wallet, and a chain that hols my work security card around my neck.
they didnt attempt looking in the boot, they didnt even do any damage at all to the car, closed the car up, and walked off with just two things.
So dont stress about the boot being opened.
alternatively, you could wire it up to the overhead light. it has a time delay on it, so when you open your car, power will be on, you can press the button, as the light fades, power is off, cant open it. then flick on internal lights to get power again.
dont know if it would work, but i dont see why it wouldnt, good luck, tell me how you went