Does anyone know how it is in Singapore? I saw some videos on YouTube and it looked pretty good to me. Also I am assuming most people just pay cash to maintain privacy. I was looking at going to a massage parlor or establishment. Any recommendations for such places in Singapore? Most important thing for me is that it is legal. I am surprised how so many hobbyist are going to many countries etc. without caring about the legality?

The hobby is legal, but if you are caught with pornography, it's off to the slammer for you.

Don't forget..  Largely chewing gum is a punishable offense.

Just don’t steal any road signs

Used to live there many years ago.  There are designated brothel areas with mostly Thai and other east Asian girls. Not bad but service is pretty formulaic.  Other option is 2nd tier hotels with "spas" most of whom provided covered FS.  And then there are the special bars on Orchard Rd where visiting girls can get picked up for a hour or an evening - nice cuz there's a wide selection you can pick from.  

and prostitution is legal but only in the designated brothels. Street or escorts are actually not legal. The hotel I was staying at seemed it might be a bit strict, unlike other Asian countries, regarding female guests. That's based on seeing one hooker there who approached me.