I'm probably parroting stuff that's already been said in this thread at one point, but I just couldn't resist adding my opinion.
I wouldn't go so far as to say that master > apprentice forever and always. I'm not going to quote any movie fights because I honestly don't remember them all that well, but I can easily quote from experience with real swordsmanship. 95% of the time if you're fighting someone who could be considered a "master" level swordsman/woman, you'll get your ass kicked. Like, real bad. Doesn't matter if you're a 'prodigy' or 'the chosen one' or whatnot. That person has had more real life experience with fights, they have more duels under their belt. You'll most probably end up dead/maimed/unconscious pretty quickly.
That being said, cunning and wit can give you the advantage even over the most powerful of fighters, because you essentially bypass their venue of attack completely. So it's not impossible, but it's certainly hard and probably dependent on luck quite a bit as well.
As for overpowered FUs... idk. I'm all for those who decide to specialize in the Force and really learn a wide range of powers and are above-average with most of them. That is awesome and cool and really shouldn't be a reason for derogatory remarks. But as [member="Xhexania"] has pointed out already, even the most badass and trained of FUs are going to get tired when they do a lot of powerful stuff. Also like she said, if people started writing about consequences of their Force usage (on their level or not), it would be awesome. It would dissuade many from spawning high-tier stuff w/o pause, imho. It could also provide a window of opportunity for the opponents who aren't as skilled in the Force.
As for NFUs against FUs... either go Order 66 on them ('cause no-one can deflect that many bolts at the same time) or listen to the
friendly advice of our favorite non-meatbag.