alarm as remote key only

some of you may remember that my cars 3rd party alarm installation was causing problems...

Well, I had an idea.. Can I install it and wire up ONLY the power and the door lock/unlock trigger, so it acts as a remote key?

Perhaps the trunk too, as it has the wire for it (but no idea which button on my remote does that---the labels are long gone)..

would this work? or would it constantly trying to use the siren, and waste my battery? (no siren attached)