With all the security alarm systems I've seen, they divide things into zones and when arming them you can not arm that zone. In the old place, I'd turn off the motion detector in the basement (they would have set off the alarm before that going through the windows or sliding glass door) as for a long period my dog was down there roaming around. For those with sensors on the garage doors, it may be better to disarm those in case you come back home and end up chatting with a neighbor. The glass break detector they had in my old house was almost useless as it was a good 15-20 feet from the windows (and that was likely at the edge of their range). There are also good and bad monitoring companies. Sometimes the bigger they are, the worse they are.
Phil and Tom,
Yes, all of the systems today have several zones whether they be hardwired or wireless. You can bypass any zone that's are not a 24hr zone like smoke detectors, flood detectors, panic alarms and so on. Some people only use their perimeter zones and not their motion detectors because they have pets and the detectors are not set up for those pets like I mentioned earlier. The problem with only using the perimeter doors and windows is if someone breaks the glass and crawls thru the window or sliding glass door without opening it they just beat your system. Glass break detectors only work in the room they are in and it gets expensive to put them in every room.
You are both correct that it is very important to have the right alarm company and monitoring service. As a rule, the bigger the company the harder it is to work with them and the higher their monitoring rates are. Their rates are higher because they offer systems for very little money down and subsidize the loss with a higher monitoring rate which they lock you into under contract. In the end you pay a lot more for your system than you would have if you purchased the system at the time of installation and gotten a much lower monthly payment.
Tom,
you are very welcome, if you have any other questions feel free to ask, I'm happy to help. If or when you are looking for a good local alarm company in your area shoot me a PM and I will call my supplier ADI. They usually have a list of local companies they work with at each branch and they won't give them out unless they are comfortable with that company. I suggest you stick with a local company who owns or uses a local monitoring service. You will typically get better service and if the central station is local they have a much better idea of what's going on such as a wind storm or a power outage or what ever natural disaster is happening at the time.
Take Care,
Greg