Annointments : remove them or change them to be insignificant like luneshines in the presequel. anointments ruin build diversity but it sometimes makes certain builds stronger but it also makes the unique builds weaker becaues of the mayhem scaling that exists. ex urad setup radiation flak.
Mayhem Modifiers : remove them, no one wants them in the game, its not fun, its annoying. annoying does not equal hard.
Unique Loot : make most of the guns viable to a degree. i understand that there needs to be meta weapons but i feel like 70% of the unique loot in bl3 is just overlooked because of how strong another weapon is.
Classmods : dont make bad class mods =). zane is a prime example of terrible class mods, the only way to get to mayhem 10 and successfully do damage comparable to the other vault hunters is using seeing dead, if they just changed abilities that would go with bad class mods or buffed the abilities of bad parts of the class mod then there could be more build diversity.
Mayhem System : now im unsure if this would help with the game much but i think being able to skip mayhem levels is a bit absurd when there is gear linked with the mayhem system. going to mayhem 10 after beating the story and farming venders seems broken to me just saying.
Bosses/Raid Bosses : add Raid bosses as them selves, i dont like that you have to go through a mobbing simulator just to take on a “raidboss” at the end of it. also raidbosses at the end of takedowns dont really feel like raidbosses. i like the idea of a builds surrounding the fact that you are taking on a beefy monster with some ads here and their for some kill skills.