Replaced battery in remote, even reprogrammed the remote, and it worked. It'* now intermittent...every once in a while, all the buttons decide to work perfectly. Then suddenly they all stop.

I go to unlock with the key and my alarm goes off, and the only way to stop it is by unhooking the battery.

Ideas? (I just don't use the remote at all anymore, but I have a few days of free time so I'm trying to gauge any projects I can work on).

Is this your factory remote or an aftermarket remote such as for a remote start?

Factory remotes.

Also, my trunk key does not turn in my trunk.

i work at a gm dealership fix remotes all the time . first take remote all the way apart. check the board where the button contacts are they can get dirty . if the board is black then the carbon like material on the rubber pad is no good . either need to find new or differant pad. then clean with rubbing alcohol.
check the battery holder on the board if its loose needs to be soldered. gm had a big problem with that . your trunk lock spray some pb blaster inside it let it soak in . maybe more than once if it turns then spray wd-40 in there . if it keeps working then give it a shot once a month . hope this helps you

Was going to say what he said. ^^ good post

hope it helps you out

I posted about this a while back and someone suggested the ground bus cable harnesses were dirty, as this was another typical problem of our cars. I have not made an attempt at cleaning these myself yet. I have taken the remotes off my keyring and disconnected the horns entirely... Got tired of hearing the neighbors complain about the horn honking by itself.

Well my buses were perfect, my board was clean as a whistle and soldered tight, still no luck, and jumping the OBD connector to reset didn't even work.

And key still won't turn in trunk. It'* all just stuff I live with now...I ignore the fact I have key transmitters and lock and unlock by hand only, and I only use the trunk release button on the door.

time to take the lock to lock smith have them work it over for you . how are you trying to program the fob. with a jumper wire or a scan tool

Jumper wire.
And the lock isn't a big enough issue for me for now...jobless, much bigger issues to tackle.