The questions were confusing, as they contradicted each other enough to make a single response useless. Yes, I support legalized prostitution.
As my major was history, the whole concept of prostitution being 'morally wrong' in the first place was introduced in western civilization by religious dogma and carried on through the foundings of certain countries (ie: America, the Land of the Free - as Long as You're ONE OF US). For the most part in human history, prostitution fell into three categories: religious service, government regulation, and criminal activity.
Religious service was simple enough - the temple prostitutes of Ishtar who lived a pretty good life being the best example. The Sacred Harlot having a specific role in society by providing services for one of the most basic needs of man/woman. Retirement was pretty damn good and you had as much power as the priests and nobles.
Government regulation - Rome being the most documented in such practices, where there were certain grades, taxes, and laws regarding types of services offered. Like any other government agency, you had the top-of-the-line courtesans earning just as much as the emperor and you had the bottom-line grunt workers barely able to support themselves. It was a business, and you were your own business manager.
Criminal activity - usually decreed by whatever religion is in power, as the politicos usually had their own prostitutes and call girls so they had no interest in ending a perfectly good service. Brothels and the like were tolerated, but the women (and men) working there encountered so much stigma that it became a shameful means of supporting one's self. Making it criminal meant that law authorities did not have to ensure people's safety, diseases ran rampant (because 'you deserved it for going there in the first place'), and even if the place did get the attention of the rest of society, there was no sympathy from the masses.
Down to it - make it legal and that'll get rid of some of the 'forbidden fruit' aspects. Put them in mid-grade hotel rooms with a blood test in a waiting room, that'll cool everyone's jets.
(Although, I personally like the concept of Lady Sally's House created by Spider Robinson in his 'Callahan Universe' - an independently owned brothel run by a professional prostitute and business woman who has her own doctors and bouncers on staff, and who screens the clientele herself. The best food, entertainment, rooms, and intelligent prostitutes who can hold conversations as well as they perform their jobs. I'd love to go to a place like that.)