If it is not stated in the reward - It will be USB 2.0 , Read speed up to 22Mb/sec, Write speed up to 10Mb/sec
To upgrade - just add $5 to get USB 3.0. Read speed up to 31Mb/sec, Write speed up to 20Mb/sec
And there USB 3.0 for $45 & $75 reward.
yes, definitely (write me a note when the funding be successful - and I'll not glue the flash drive to your case). You also may buy the case without the flash drive.
Don't see the answer to your question? Ask the project creator directly.