Can another signal sources such as a garage door opener or a TV remote disarm my alarm, I have heard that they could and that is the reason for the auto re-arm feature?
No only your remote can turn off the alarm. The reason for the auto re-arm feature is in case you accidentally press the unlock button. It is added protection. We have had a few complaints about this feature being over kill, but nobody has come back and said “my remote was in my pocket and I accidentally turned the alarm off and my bike was stolen!