Nothing particularly wrong with the list, although you might want to take some more dispel scrolls.
4x CoC and 2 hydras isn't necessarily bad or even risky. However, for the core choices I'd try something like 1x dark riders and 2x or 3x crossbowmen to hold the home quarters. The crossbowmen units could also harbour the sorceresses in the start of the game if needed. As far as the lord choice is concerned, I'd probably go with the pendant dreadlord on dragon or the supreme sorceress on pegasus to save points and buy a third level 2. With the focus familiar you're not gaining a lot from the dragon except the terror checks. Either way no matter what you do you'll be okay I guess. I won a reasonably large tournament with dragon + 3x silver helms + 8x tiranoc chariots high elf army two years ago, and in many ways it was similar to this list. On the dragon I used a loremaster prince with his pockets full of dispel scrolls and absolutely no protection