Hello and
Security :
like they said the only person likely to be inconvenienced by an alarm is YOU
A disc lock with a reminder lead around your twist grip is OK but better by far is big old chain and padlock through the rear wheel.
I have trackers fitted to my bikes. It doesn't stop them being stolen but it might help catch "the little shits what dun it".
P.S. never tell the Insurance folk what you do to protect it as they will make it a mandatory part of your policy.