If a pro tries to break in he most likely cut the phone line sign or not. If you went to the trouble of hardening the alarm system why not do the same for the phone line. Also half a dozen dummy security cameras will go a long way to avoiding a break in whether it's a pro or amateur. The dummy cameras don't cost alot just be sure and get some that have a battery operated red LED on it and add a small piece of wire going into the attic for that little touch of realism. I don't know about your alarm but mine has a setting (instant) to set it off as soon as the contact is broken. This leaves no time for anything.
Do not under estimate anyones ability to find out where you live or just catch you making a stop on the way home. If you think they are serious with the threat your only options are legal fileings. You can not legally be proactive to circumvent the threat. You have to wait for them to make a move. Good luck.