So the other day I reversed over a wheel chock and now my right rear tire wont hold air. This REALLY sucks because I bought the tires 1 month ago, maybe less. Is it early enough that I could replace the one tire without messing up the AWD system? They have mostly highway miles on them and even at that I only put probably 1000 miles since I got em.

If I could get by without replacing it I would like to. All the cans of "fix-a-flat" I have read say its only teporary and can corrode the wheels. Is the tie slime more permanent? I dont even know where its leaking. It may just need reseated on the wheel. I am hoping this is the case. Do you think it could be that?

Don't use fix a flat - it will mess up your TPMS sensors and wheel etc with all the gunk. If you can't see an obvious leak, take it to a tire shop. They can dunk it in a tub of soapy water to see where it's leaking from. If you have to buy a new tire, you most likely can get away with it since you only put 1k miles on the tires. You could use a tire tread depth gauge to check the depth (be careful though as some of those gauges are off). A ruler may be more accurate in some cases. If it's off by more than 1/32", I would consider getting a new tire from tire rack and having them shave the new tire for you.