It is my opinion that it would definitely hold your 65 inch Samsung curved TV. Mine is a 55 and since they really don't weigh much anymore I would say that you wouldn't have a problem using this model of wall mount for your curved TV
YES so long as the back of the TV has the holes in the back for mounting. They usually all do nowadays. I have mounted LG 60" curved with this mount. It comes with many different size screws for most models
This mount comes with a large variety of TV screws and a set of spacers. It fits numerous TVs with flat backs and other shaped backs. I would try it out if I were you...they include many different sizes for various TV backs.
So far I have not found a tv that i couldn't mount with this bracket so I am going to say yes as long as it isn't modified form original on the back of the tv for any reason