Meh, first play through I don't see much point in not levelling. Actually on any play through I tend not to bother with keeping levels low. Apart from not minding fighting hard bosses, I'd rather be focusing on GF abilities and getting good magic to Junction.
First play through I think you look like you're doing fine. The more you play the game the better you get (which is one reason I like it), it's not just about levelling up and collecting everything, the more you know the game, it'll get MUCH easier.
My advice would be to start playing with Junction if you really want to be good. There are a lot of tricks that you could learn that make the game really easy but I wouldn't worry about them, just play it naturally first run through.