Got a situation...help? (long)

[ASTAR]

Ok so I bought my Hummer at Putnam Hummer in Burlingame and so far so good. I had to take it in today (6 days old) for the loud wind noise coming in at the windshield, one key remote didn't work, the driver side mirror shook a little, and there is a slight vibration that comes on from 75mph to 80mph. The windnoise was horrible, hard to even talk on my cell phone while crusing down the freeway! The key remote, slight irritation (read no biggie). The mirror, also slight irritation but the concern of it getting worse is what prompted action. The vibration... this is my other big concern. It is a slight vibration but I can feel it. The worry that I have is that it goes into the shop Thursday for a lift kit (6" Fabtech) and I know that if the driveline is bad, they'll blame the lift and I'm on my own. I need to establish a solid baseline before modifying. The service advisor said that the tech believes its the tires being out of balance slightly. I don't agree. No I am not an ASE certified mechanic but I have built a lot of 4x4 trucks and such as I used to own a 4WD shop and know what a driveline vibration feels like.
They are going to rebalance the tires for me in the morning and I am to pick it up. I am in a bit of a pinch though because my H2 needs to be about 150 miles away from the dealership tomorrow because my dad bought my stock tires from me for his lifted (getting done tomorrow) Chevy that he just bought. He needs the tires tomorrow, I have an appt to have mine lifted the next day and I am worried that it will still have the vibration. Then when i bring it back, it'll have the lift and again, I'm on my own. I would just put off doing the lift but then I screw my dad. Hopefully they will tell me that the tires didn't solve the problem and they have to order a driveline. I can take my H2 and get the lift done and bring it back next week for the driveline install. I don't see it working out that way just because my luck isn't that good. Anyone got any ideas or had the vibration before as well?

As far as the other things, they are replacing the mirror, doing the windshield fix, and a new key remote so all is well there.

They gave me a new Buick for a loaner (from Enterprise) so it sucks driving that when I was just getting used to the Hummer. No Nav, XM, steering wheel controls, coolness
Can't wait to get my new baby back and hopefully by Saturday it'll be better than ever!
I am also installing a Flowmaster American Thunder cat-back system, Hypertech Programmer, and an Airaid intake filter kit, HID light ballasts, and some billet stuff on Saturday.
WHEEEEE!!!!!