Sure, you're allowed to have an earlier NRA than the latest allowed by law. But we're contemplating making the latest age later, which would only be of interest to plans that want to use the latest possible NRA.
I don't know about the employee thing. This is what IRC 411(a) says:
and 411(a)(8)
Says nothing about being an employee on the date they attain normal retirement age. I also don't see anything to that effect in the 411 regs. I would be happy to be proven wrong though. The way I read this, a participant who defers their distribution (and is eligible to do so, i.e. not subject to mandatory cash-out) until NRA becomes 100% vested.
Interestingly, though, our plan document (FT William cycle 3 401(k)) only says that "a Participant shall become fully (100%) vested upon his attainment of Normal Retirement Age while an Employee."