Also, looking at your list, you have taken the same item twice, (Banner of Wrath) which you cannot do. You unfortunately are unable to take the same magic item twice, even if its a Common Magic Item, or Army Specific.
the 25% Core rule is based off of points. So if you have a 1500pt army, you would have to spend a minimum of 25% of your points on core units. You can certainly go over this option, and for Warriors of Chaos fielding the best infantry in the game why wouldn't you? But for powergamers or minmaxers, they wouldn't normally do this.
Just so you also know, You cannot combine certain items, breaking down your Exalted Hero on Barded Steed. You gave him a shield, which is fine, but also a Halberd, You cannot combine the two at the same time. Normally thats not a bad idea, but then you also gave him the Chaos Runesword, which is a great item, but you seem to have wasted some points on the Halberd, which you would certainly never use.
Also, I don't have the book in front of me, but does it say you can take Mutations in addtion to magic items? Such as 50pts of Magic Items AND 25pts of Mutations?
But if you were looking to get an army going, I would certainly go for the Battalion Box set, you get a lot of stuff in it for relatively cheap, I think adding it all up you save roughly 20-30 dollars. You may not think you would ever use the warhounds, but trust me, a 5 dog 30pt screening unit is incredibly valuable in such an elite army. Also they can march block, and possibly get in a flank charge now and then, which is also very handy.
