I use a 12/8 Elf Ftr/Wiz. I use EK tree just to 2nd Core, but use the Improved Shield and the Arcane Barrier.
I use the Elf Cores to improve my Point Blank Range and to Unlock AA and for Grace (saves on needing Bow Strength)
The rest is spent in the AA Tree.
Now I like the direction of adding Spell Power to the Imbues. I like the idea of adding Enchantment to the DC bonus. I've been thinking about TOEE Bows for Spell Power and Thunderforge for DCs (being Two Handed has an advantage) - So there will still be lots of reason to Switch - Such as DC to CC the room and switch to Spell Power to grab that extra damage or kill the boss.
Now I understand if on the DCs that Dexterity may not be on the table, but please consider Intelligence and Charisma as options as well. That way the Elf AA builds can also be an option with the DC options. I ask because my main attribute is Dex but I can balance out Dex and Int to have a decent DC for CC options.
I really am looking forward to seeing how the Elf version pans out...