Percentages are calculated, just unseen for you. They're based on your level and your opponents level.
You need an X amount of accuracy to cap out on level 50 mobs, it's a static number, it's all the same.
Crit rate is based off your native amount of crit rate at your level, and every so many points give it an extra %. Large amounts of points needed for it, i'll tell you that.
It's early and i just woke up, but the only one i know off the top of my head is Skill Speed.
Every full 10 points of Skill Speed over the amount you natively have at your current level takes 0.01 delay off the timers. (If you have 249 and get one more point for 250, your delay is now 2.49, or if you natively have 351 and you add 9, your delay is also 2.49). So if you got gear with Skill Sped +100, your auto-attack and ability delay would go from 2.50 to 2.40. Trivial and not worth the effort or the loss of stats elsewhere. Especially since if you would have filled that with STR, every 7.4 points of it would equal your raw weapon base damage being +1. Only reasonable piece around AF levels is Odin's armor. Same relative stats as what AF gives you, just with extra determination and +50 Skill Speed.
Long story short. Get accuracy up to a certain point and stop, focus on your main attribute stat all the way, add in critical hit for whatever you cant get. Everything else just isnt worth the effort for a melee.