I would think Sony would know to take television regions into consideration.
Thing is, is the PS3 you bought for another region- made for Japan, let's say? If so that would explain part of why it doesn't include the 50 hz settings. Your tv sounds like it is not well suited for the PS3 due to the resolutions you give- the majority of games will play in 720p. You'll find all games going to 480p on that.