A:AnswerYes. Just format it in fat23. Should be able to use on both systems. I formatted my on my Mac from the first and once I used on my windows pic there was no problem.
A:AnswerNot directly - the Passport is a good place to archive - by putting the file from SD Card to Laptop and then plugging Passport into the Laptop and dragging and dropping. but *not* transferring as you asked.