Be able to putt 95% from inside 20'. Nobody should be missing those in Open, unless you are me
Average 1.5 putts between 20' and 40'. This goes towards putting percentage on the first putt and the second. Part of being a consistently great player is avoiding three putts at all costs while still make a fair percentage of longer putts.
Be able to hit a 10' wide area 100' out on your driving line, and a 20' wide area 200' out on your driving line. Being able to hit your driving line precisely will keep you on the fairway and get those few extra feet towards the basket that earn extra birdies.
Be able to land within your "gimmie" range on a 300' wide open shot, and every other range extrapolated from this figure. My and most people's gimmie range is 10', ie the spot where you just can't miss and if you do it is because you didn't care or a bee stung you. That means at 50' I need to consistently be within 2' of the target. At 400' I need to be within 13' of the target. Keep in mind that a pro gimmie range would be greater than 10'. Target accuracy is important and combined with drive line precision is what generates birdies.
Know how to judge shot distance within +/- 5' and how long each of your discs are. Playing pro means playing tourneys, which means playing temp holes. You need to be able to hit the distance precisely on a shot you have never thrown before.
I don't care if you can throw every style but you need to be able to get every flight path out of your discs one way or another.
Thats what I can think of right now.