I noticed a humming type sound from the engine compartment whenever I remotely unlock the doors or open a door. Anyone know what this sound is?

It is the SBC pump getting ready to work for you.

That's right - and if you pay attention while driving you will also hear it and feel it via the brake pedal once in a while - which I do not like. Anyone else feel/hear it while driving?

i hear and feel it, but it doesn't bother me much..

and the height of my car always seem to be different each time i park...why is that?

juke, this also happens to us, i think it happens because when you sit in it, the car lowers a little bit

I think its dependant on brake usage while driving.

I too have noticed that humming rumbling noise from time to time while driving and almost always when first getting into the car in the morning. It is a bit annoying.

I also notice that when driving in my office garage, up some ramps going very slowly that the car seems to hesitate a bit. It seems like the tach shows the engine slowing down around 500 and then it revs up making a strange sound like recovering from a stall. I only notice this when going very slowly - perhaps it is gear searching?

Yes, I've noticed it to while going up ramps. Almost as if it is going to stall.