I'm not an expert in pi, but I do believe this is all achievable. Firstly, your sound and video outputs shouldn't be a problem. With the earlier pi boards you got a yellow rca video connector. I'm certain that if your CRT TV has a scart on it, you can get a connector that goes from 3 rca plugs to scart. You would then just need a wire that has 2 rca (red and white) to 2.5mm jack (which plugs straight into your pi).
As for booting straight to the video player, someone else might want to chip in here. But I'm sure there is a file on the pi called local.rc which allows you to set things like this up. On my build I know for sure I have this file, and I've heard of people setting values in this file so that on retropie instead of booting to the menu, you can set it to boot into 1 specific game.