#3: Confirm the handling of unused vacation days
Absolutely. I knew of one person who had in advance of the resignation scheduled vacation time that ended at the end of his/her employment, and nearly didn't get paid for it. At that firm, vacation time wasn't "earned" it was "made available" (or something like that).
Actually, he/she didn't get paid, until a lawsuit was threatened. There was a memo confirming that the vacation was approved. The way it was worded, it showed a definite clear commitment on the employer's part. Clear and definite enough, anyway.
--- slight topic change ---
Seems to me the whole matter of providing for turnover/transition would be a bit difficult if the last week (or was it two?) was spent out of the office on vacation.
Perhaps -- and I have a vague recollection that this was so -- the employee performed in a professional manner the turnover/transition before leaving on vacation.