AFAIK, United's class seniority has always been based on last 4 of SSAN.
For hotels, I posted this on another board. Take it for what it's worth:
For a place to stay, pick a hotel chain and join their frequent guest program.
Specifically, I'd recommend Marriott because I find you can go cheap cheap and still get great perks.
For the Denver area, the Fairfield Inn Aurora (not too far from TK; I've stayed there before) is $89/nite for 11-23 Dec with/without military rate. Go without military rate and use Premium Pounds coupons. For Fairfield Inn, you can use 50 Premium Pound coupons, saving you ~$50/nite off the rate. Coupons are good for two nights and can be had for ~$40. So your net cost at Fairfield Inn is around $59/nite. Includes free highspeed internet, complimentary breakfast and a kitchen.
Or, you could stay at the Rennaissance right next to TK. The rate is $140/nite, but you can use 100 Premium Pound coupons, saving you ~$100/nite. Coupons can be had for ~$70. So your net cost would be $75/nite, but no free highspeed internet or breakfast until you become a Marriott Gold (50 nites in a calendar year) and no kitchen.
Once you hit a status with a hotel chain, they treat you great. I'm a platinum with Marriott and I get free suite upgrades, complimentary breakfast, lounge access, etc. Plus I accumulate points for free hotel nights.
I recommend that you spend a little time at
www.flyertalk.com on their forums and get more information on frequent traveler programs and how to play the game. Every hotel chain has a program, so whatever one you decide on, I'd stick with it.
As far as the Premium Pound coupons, I don't sell them, but you can get them on Ebay and a number of other sources. They also are Bonus Bucks and Extra Euros. All are denominated in the particular currency (Pounds, Dollars, Euros). The most bang for the buck is Premium Pounds.