Duplication of information is a major problem there.
Buffs on your player frame, and up in the corner where only one is needed.
It looks like you have 4 or more different addons displaying the duration of your debuffs on the targets, and your cooldowns.
Some degree of redundancy where information is hard to miss can be a good thing, but that is excessive.
Decide what you can read easier, numbers on icons, or bars and base your display around that.
You seem to have party frames visible in raid, which arent really necessary either.
Conflicting addons trying to do the same thing with both Minimap Button Bar and Minimap Button Frame both trying to handle minimap button management, where only one will do just fine.
A well set up raid frame will replace decursive, or should you not on that character need the information that a raid from provides then decursive may be sufficient on its own.
Bag and Micro Menu (character, talents etc) don't need to be visible all the time, and should be on mouseover only.
MSBT since you seem to have reduced it largely to buff annoucements is rather pointless so I do agree with getting rid of that or at least saving it for something not easily covered by another addon.
What I would assume to be your target of target frame also showing buffs which is totally pointless.
Mario style graphics are all well and good if they serve a real pupose, though icons or bars could be more appropriate for something with a duration or cooldown or something like the ring in the middle being rather more subtle and where you should be looking instead of over to the side.