Problem is, under your rule, every time Jamaica kicks lumps out of Kenwyne, he's off the pitch for 5 mins and the team committing the foul has an advantage!
The rule I don't like is when a keeper fouls a striker (not necessarily intentionally) when he has a goal scoring oppertunity and is sent off as well as conceding a penalty. The attacking team get a penalty and a one man advantage. I think the referee should decide a) was it a penalty and then b) was it an intentional foul worthy of a red card.
Yes, I know there will be mistakes, but a keeper has to go for a one on one and if the striker is too quick, the keeper is penalised twice. A defender can foul in the penalty area and not be sent off.