Thank you :) Calling the police would be ideal, but then you have to involve an alarm company and use their system. They are expensive, and I wanted to build something myself.

1. Hm, maybe. If they were to arrive, they would have to call me — I could remotely disarm the system or give them the code.

2. Not sure, my closest neighbors are aware of the alarm system. No false alarms in 13 months I've been using the system.

3. I used to work as an alarm technician; you can't really prevent the pros breaking in, getting what they came for and getting out. But you can prevent someone spending a long time inside the house looking for things to steal.