It's as finished as the game is going to be at launch, this isn't "Early Access" where the game is still evolving. You can talk all you want about how games are released unfinished these days, that's fine, but make no mistake. "Advanced Access" is the game as it will be on release day, with access granted a few days sooner. It is NOT still in active development as an unfinished product and is not going to see significant changes between the start of the Advanced Access period and public release.

Advanced access is playing the game in it's Launch Day state, and any rules for time played should be consistent between Advanced Access and official launch. Your first two hours in Advanced Access will be the same as the first two hours if you only started on launch day. It's the same game with the same refund rules, not your opportunity to red-eye your way through the whole game for a few days and still get an uncontested refund.

The "bad move" is a customer pre-ordering in the first place. We, as consumers, should know what's up by now.