A few general questions about AEX (n) before I buy

Before I buy an AEX, I thought I'd ask a few questions. First, my (hoped-for) setup:

500Gb Time Capsule + DSL Modem
AEX in another room + XBox 360 (using CAT5)

1. Since I only have one modem, one account, etc I would set the AEX using WDS, right?
2. I believe I read somewhere that WDS ?halves? the connection speed of ALL devices on the network?
3. I don't want the AEX on all the time for both power draw reasons and longevity (as well as minimzing any performance impacts from WDS when not in use). Are there any problems with keeping it plugged into a power strip and turning it off when not in use? This is obviously the same as just unplugging it, so I was curious if it "tends not to do well" in those situations or if it could care less.
4. AEX as a portable wireless station means I could be in a hotel, plug an ethernet cable into the AEX, configure the AEX to be a base station then I'd have wireless in my room?

Thanks in advance for the answers. Feel free to elaborate where I've left something out or offer other solutions of which I might not be aware (that do not require any wires other than "wall to modem to TC."