Depends. This mouse requires the standard USB type A port to work. New 2018 Macbook Air with only Type-C ports will not be compatible.

There is no significant difference, Bluetooth however, is slightly more efficient.

Brand new battery with 8 hours of daily usage, can last for about a month.

The trackball may get sticky when it gets dirty, so it is designed as a seperate piece, you can simply push it out and clean it.