has it right. The example character would have Badass Fighter 2 / Fighter 1 and the character would gain the 4th level bonus feat if he became a Badass Fighter 2 / Fighter 2.
Also, added a couple more feats. I may need to clean them up a bit though.
I'm sorry, I misread what your were saying. Your proposal has inspired me. As I ponder the subject, I must confess that I fear for any group that allows a PC 20 Badass levels. I mean, imagine if a Welch-like player got ahold of this system.