I have never seen a 30 ft putt from the fringe only go 2 inches. My guess is that it was some sort of bug... presumably from there being a difference between the graphics display of the immediate area and the data that churns out the numbers. The game presumably keeps track of the area on the course by using little blocks of area... maybe 6" by 6", and you happened to catch a corner of the rough, even though it appeared to be fringe on your screen.
That said, it must be a pretty rare issue b/c I've never seen it.
Being a pro or master is pretty easy. It's hard to say how much the clubs and balls have to do with it, but probably a decent amount. I'd guess that my set of good clubs knock about 8 points off of my average. I'm not in the business of helping competition, but all you have to do is think logically and methodically. If it seems like something is consistently failing to work for you, then don't do it, and vice versa. You will find yourself coming up with ideas.
One idea that I'd suggest to you, which you may already know, is that sometimes the pin is in a super hard location, and it may be nearly impossible to stick the ball in the immediate vicinity of the pin (esp if you aren't using balls that have spin on them), so look for an easier part of the green to land the ball at. It's better to get on the green 99% of the time than get on it 50% of the time 10 ft closer, but also have to deal with the other 50% of your shots being from the rough and sand.
The same goes for laying up. The hole location might be easy, but the fact that I'm 240 yards out makes it very difficult. If it takes a miracle for me to squeeze the ball in between two hazards or two flanks of rough in order to inch up onto the green, then I will usually just lay the ball up. I'd rather deal with a 60 yrd shot from the fairway, which I can get within 5 yrds almost every time, than a 50% chance of having a 30 yrd flop/pitch from the rough or sand, which might end up in a disaster.
Try new things and come up with new ideas. Remember what works and what doesn't work. You have to break the game down into a science. Guesswork isn't going to get you very far.