I actually don't know any frame traps lol. And yeah I should work on combos, I only know the absolute basic stuff.
With tentarafoo do you mean during blockstrings?
Frame traps are basically leaving enough gaps so the opponent can mash but will still get hit in their start up. For anyone, you can do this by delaying your normals a bit before pressing the next (like doing 2A *pause* 2AA etc). Yosuke's 5B gives him +1 on block, so if they're mashing on anything that's not a DP or a super, they'll get CHed by a following 5A. I'll generally end blockstrings with this to maintain pressure. If you get them to turtle and respect you, that's when you start throwing in grabs, 5D (for more pressure) or AoAs in your game.
I think tentarafoo in general. I use it quite a bit even as a reset, but sparingly. It's a good move to catch people off guard, and I think your opponents fell for more than they should have. Sometimes it's a good thing to use something less, even though it's good on netplay, just so you can spend more time improving on finding other ways to open people up consistently. When you do use it, you can experiment more like OMCing and comboing off of that or regular throw.
I still use Yosuke from time to time since I think he's an interesting character, so if you have any questions, just ask.
If you're looking how Japan's Yosukes are compared to ours, this is a good video to watch
http://www.youtube.com/watch?v=x7vFebGAIks