Legalizing prostitution isnt going to help the rape issues. Different beast. It would give the prostitutes a great deal of protection, and even some decent health care.
I used to be only for medical marijuana. I still mostly am. I'm beginning to lean toward full legalization. SativEx (a nasal spray of cannibinoids) in Canada is extremely expensive. About 5x the street price for decent bud, for comparable doses. The sin tax could help the state's and fed's coffers. It would halt crime associated with the drug. And those who need and use it medicinally would greatly benefit from no longer having the Feds looking over their shoulders. Edited to add it would free up the legal and jail system too.