Yes, you can.
no
No you can't.
You can use any USB Storage Device (such as a thumb drive or an external hard drive) to store games, saves, Gamertags, or media on. But, it is better to use the Official Xbox Thumb drive or the Xbox Hard Drive as they are both designed for use with the Xbox 360.
yeah
No, you cannot use an external hard drive on the Xbox 360 to play original Xbox games like Halo 2. The Xbox 360 is backwards compatible with select original Xbox titles, but these games must be installed on the console's internal hard drive or a compatible Xbox 360 hard drive. An external hard drive can be used for storing Xbox 360 games and data, but it won't support original Xbox game playback.
I believe that the 4 gb xbox 360 you are talking about is the new slim. There is no way to use your old hard drive with the new slim xbox. You will need to buy a transfer cable to move your saved games to the 4gb hard drive.
Simply remove the Elite hard drive from the Xbox360 Elite and insert it into the Xbox360's.
All Xbox 360's are basically designed to use a hard drive, so an arcade version can definitely use a 20 Gig hard drive, but if you may have to recover your gamertag.
The Xbox 360 Kinect sensor is not compatible with any Xbox One console you can use an external hard drive to store games, apps, and console settings for your new Xbox One. The external hard drive must: Use a USB 3.0 connection.
You Can Use USB Hard-Drives But They Wont Be Able To Do The Same Features As The Official Xbox 360 Hard-Drive And You Will Only Be Able To Use 16GB Of Memory.
Yes. There is no point in buying a brand new Xbox 360 with hard drive because you will not use that hard drive. The arcade edition has no hard drive so you can use your old one. Also on the plus side, its cheaper.