the chaos dwarf units are too small and weedy, they’ll never survive more than one round of combat, and thats bad, as their some of the best troops you have.
on the flipside, 11 BC is just too expencive TBH, 'd say just take a unit of 5. He’s DE, he’s going to outmanouvre you no matter what you try, so go for a static army for him to bash against, not one huge train of BCs
also, one lvl 2 sorcorer isn’t very effective, because DE are a highly magical army, and with their casting prowees, and the fact he’s probably packing 2+ mages, I’d say swap the level for two stones:)
I agree, you need to buff up your units of warriors and cut the bull centaurs. I would also cut the death rocket and run an earthshaker in its place, and swap the BC hero for another mage with a scroll or two. After these changes you should have some points left over, which I would spend on some naked hobgoblins. These are terrifying for dark elves, because they hit and wound on 4s and are 1/3 the price. Hope this helps