Killers should have 5 perk slots
I think we should see perks with "weight" depending on how impactful they are on a game. Survivor perks have a lot of weight because the meta is very strong (Dead hard, CoH, DS, IW, etc). This wouldn't be a problem if it wasn't because all 4 survivors run the same meta perks every time.
But sadly for killers, even a meta build is outweighted by survivor's meta. It is 16 perks against 4, after all. And to make things even worse, as a killer you need to "give up" on a slot for a slowdown perk if you don't want survivors tbagging at the gates at the 5 minute mark. So, you already have one less perk slot for the fun build you were planning.
I think 5 perk slots for killers would relieve some of the limitations killer builds have, and you actually could have a chance to use a build without feeling like being genrushed.