Hi Sharla,
You asked:
Just wondering how many people have competed with an injury, what it was and what would be the cut off for you? How much worse would that injury have to be before you'd pull out?

I competed with various injuries during my competitive career a long time ago. Anyway, I've competed with inflammed shoulders, elbows, knees, and a partially torn retina. In some cases, it was okay, in others, not so smart...

The criteria I recommend you use to base your decision on whether or not to compete with an injury is this: 1) Will the injury you are saddled with significantly affect your ability to perform at your best (or at least your near best)? and 2) What is the potential for permanent damage?

Oftentimes, unless you are a professional fighter with a lot at stake on many fronts, it's ideally best to rest, rehab, and fully recover from an injury before training hard (this precludes training around an injury) and competing. Besides the aformentioned criteria, another concern is the higher probability of you being hurt/knocked out to an easier, greater extent by your opponent due to not being at full strength/capacity.

Anyway, hope this helps. Take care...