Mere text changes should not introduce unrelated bugs unless you screw up somewhere else. As Rangi said, working on multiple versions simultaneously is only going be a lot more work unnecessarily. You should work on the core features, and only then round up each version with its own text or version-specific features.
I read about that burn bug when you posted it in skeetendo, and it should be very easily debuggeable. I hope it's not the only reason you're planning to start over because you're inevitably going to introduce trillions of those bugs eventually no matter how many times you start over. Rather than discarding all the work, I'd try to learn the essentials of debugging with BGB so that you can deal with future bugs better, and that minor burn glitch should be a good place to start. Only start over if your changes so far are totally unmaintainable, and, if so, work a bit on finding out what went wrong (introducing code that you don't understand, creating dirty workarounds to solve problems rather than coming up with cleaner solutions, lack of documentation...) so that this time you can start in the right direction.
I read about that burn bug when you posted it in skeetendo, and it should be very easily debuggeable. I hope it's not the only reason you're planning to start over because you're inevitably going to introduce trillions of those bugs eventually no matter how many times you start over. Rather than discarding all the work, I'd try to learn the essentials of debugging with BGB so that you can deal with future bugs better, and that minor burn glitch should be a good place to start. Only start over if your changes so far are totally unmaintainable, and, if so, work a bit on finding out what went wrong (introducing code that you don't understand, creating dirty workarounds to solve problems rather than coming up with cleaner solutions, lack of documentation...) so that this time you can start in the right direction.