Couple things: First off, NO, Sam Boyd is not anywhere near the airport. Sam Boyd is on the far east end of town (more Henderson really).
Tickets: Not a problem at all. UNLV football is not a hot ticket, you can get a seat anywhere, not long before the game.
Lodging: If you don't need the experiece of "the Strip", yes, staying off strip can save you a lot (not to mention a lot of hassle and headache). Most of the off-Strip casinos have great prices, especially on weekdays. Sunset Station or Fiesta Henderson (rooms at Fiesta Henderson the Sunday night after Thanksgiving were $17) are two that are closest to Sam Boyd; Also, Sam's Town, Cannery East (pretty new) are not far.
Transportation: I'm a big fan of renting a car because it's so cheap and you're not at the mercy of a shuttle, taxis, etc. If you're staying off-Strip, I'd say even moreso because you aren't dealing with Strip traffic as well.
Still a long ways off but not too early to start thinking about it!!! Looking forward to this one for a while!
EDIT: I wouldn't worry about the temperature, at least not for the game. When the sun goes down, even a 103 seems pretty nice. Yes, during the day it will feel pretty hot. Game time in the stadium will actually be really pleasant.