So there is quite a lot going on in that screenshot! It isn't to my taste but regardless of that I have a couple of comments/questions:
1: Healers Have to Die? In PvE? I'm not sure why this is useful.
2: Friendly nameplates is something I've never found useful. You have buffs/debuffs on your raid frames, so what are you using friendly nameplates for?
3: Floating combat text on you is covering your meter, so why have the meter active during combat?
4: Your buffs are HUGE! Why not just filter them to show what is/isn't important to know?
5: Your raid cooldown tracker is partially covered by your range radar which makes both of them tough to make out clearly.
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If you want something really simple and lightweight, try
headline. Hands down the best simple nameplates addon, really lightweight and low cpu impact. Much, much more effiecent than Tidyplates/Kuinameplates etc. It s currently being maintained by a fan as the original author seems to have quit the game.