1 - Release the paid version when it's ready. Early cash, and free users don't care if you have a paid version.
2 - No. But let's face it, no complex software is ever finished. And it depends on the bug. Someone wants to use Lynx to access your webpage? A chinese user on an unpatched Windows 95 behind the great firewall doesn't see icon next to "post a comment"? Wisely balance the factors and just do it when you think it can make money for you.
3 - No. For testing purposes (I presume you mean the user is testing the app to see if it works for him), just make it clear that feature X and Y will be removed in Z days.
2 - No. But let's face it, no complex software is ever finished. And it depends on the bug. Someone wants to use Lynx to access your webpage? A chinese user on an unpatched Windows 95 behind the great firewall doesn't see icon next to "post a comment"? Wisely balance the factors and just do it when you think it can make money for you.
3 - No. For testing purposes (I presume you mean the user is testing the app to see if it works for him), just make it clear that feature X and Y will be removed in Z days.