1) Should I place the probe from the thermometer under the substrate on the glass ontop of the UTH? If so how do I keep the probe in place?

I use suction cup therms

2) What are the overall chances of me having to feed live prey? I would prefer not to feed live but if I ABSOLUTELY need to then I will for the snake. I'm just curious of the chances of having to.

I'd say it's 50/50 since it solely depends on the personality of your snake.

3) Should I feed in a separate enclosure or not? It seems to be preference but I'm leaning towards feeding in it's tank.

This doesn't really matter, just don't leave your snake unattended if it's live prey.

5) When should I setup the tank and everything? I'm buying the supplies on Thursday but won't be getting the snake for another week or two. I was planning on setting up the tank and just letting it sit there till I get the snake to allow me to get the temps. and humidity beforehand.

Setting it up before hand is a must in my opinion.

7) Should I buy the snake before or after I move? I'm going to be moving across town about 10 minutes away in May and I plan on getting the snake in early April but would that end up being too stressful for the snake?

Yes it might agitate the snake but remember snakes are raised and shipped out all the times with usually no problems (and longer distances)