Hopefully this doesn't add more confusion, but...

There are a few (4?) United checkin kiosks in T2 landside (I most recently used them in March), and you can use the T2 security lanes as well if you've checked in online and have a boarding pass; there is an elite security line that is marked for US Airways, but they'll recognize UA elite status as well. There are no agents landside in T2 and you can't check bags in T2.

So, if you're carry-on only and are checked in, feel free to skip the T1 zoo and go through security in T2 and walk 100 feet to the gate. However, if you need a person for checkin, then you'll need to head to T1 - use checkpoint 3 (I think it is 3) which is to the far left if you're facing the checkin desks, past Global Reception.