I can tell you have some experience with animation and line work, it just needs to be explored more. Speaking of which, I don't know anything about opentoonz, but it doesn't sound good based on how you describe it. I really do recommend Macromedia Flash 8. It's a program I use, and it can give the best results possible and I think you'd be great at it. Of course it's not free, but you can look up serial codes so you can get it without paying for it. I do hope for your improvement. Good luck!