Not sure if anyone cares but I can now answer my own questions now that I've taken delivery:

1) Does the button on the key fob still open up the tailgate or does it have to be done manually.
Yes, still opens (just pops open).

2) Without power tailgate, is there any tailgate height open adjustment in i-Drive? I still don't want it to hit my garage door when I open it.
Nope, goes all the way up.

3) When I open the tailgate, does it go up? Or does it just click open (like a trunk would), and I have to pull it up?
Clicks open like a trunk and does not go up (have to pull it manually).

4) If it has to be manually pulled up, can I stop the motion anywhere in between or does it either all the way up or all the way down.
No in-between stops, you can obviously hold in in the middle but if you let go it will continue upward.