I definitely wasn't in the big tourist hotels, English isn't widespread (it was a Brit colony), but I don't remember it being an issue, not like China.
You get the best exchange rate on the $100 bill. And you are absolutely right on the imperfect bills. The irony is that their bills look terrible. I would also recommend taking the latest version of the bill.
The banks wouldn't take any of my cards, and no ATMs. Relations have improved, so I don't know if things have changed.
I was there in 09. if memory serves.