No just one adapter per console, the hardware doesn't effect your profile as such. However you will need a Xbox Live Gold Subscription per Gamertag on your console itself.
Computer, modem, router, ethernet cord or wireless adapter, xbox, and a membership.
yes totally
The adapter connects you to Xbox Live but only if you have a wireless network and if you have a Xbox Live subscription.
None, all you need is a router,xbox live gold membership and a wireless adapter
Yes, although the official Microsoft wireless adapter costs $100...
no, you will not need the wireless adapter infact the new 360 slim has it's very own adapter installed inside the console so there will be no need for a wireless adapter
Ethernet cable or Wireless adapter Xbox Live membership (Gold Silver, etc) You can get both of these at any Walmart, Target, GameStop, etc near you.
internet a wired adapter (comes with xbox 360) or wireless adapter (I like wireless) electricity
It allows you to connect to xbox live on a wireless network
There are quite a few places where one can purchase an Xbox Live wireless adapter. Some of the places include: Amazon, eBay, DeepDiscount, and GameStop.
Yes, it is possible to use a laptop as a wireless bridge for xbox live.
It will if you buy the 100 dollar wireless adapter.