Victory! Now to add objectives to your next game 
Your conclusions seem about right - mind fog is meh, kindred archers are shruggable (maybe more useful if they were holding a backfield objective or something), strider boots or pathfinder potion are great on your cav hammer, and while the ASB is undeniably useful, giving him something to do besides stand within 6" of stuff is preferred.
How’d you like the single bolt thrower? It’s not a well loved war engine, and I dunno if one does enough to warrant all its positioning woes when it comes to LOS and stuff.
Here’s a side thought that might appeal:
Army: Elves
Points: 1000
Unit Strength: 13
230, Stormwind Cavalry Regiment
– Sir Jesse’s Boots of Striding
160, Palace Guard Regiment
165, Therennian Sea Guard Regiment
165, Therennian Sea Guard Regiment
80, Battlecat Regiment
115, Elven Archmage
– Inspiring Talisman
– Lightning Bolt (5)
85, Army Standard Bearer
– Lute of Insatiable Darkness
My brother likes sea guard, and while they pay for having both shooting and fighting, I kind of dig the flexibility. If you don’t actually have the models, guessing you could mix archers + spears in a pinch! Also got the ASB bane chant of his own, freeing the mage up to just laser stuff all game long.
Another thought on the previous list might be to swap the archers for a troop of silverbreeze? They were heralded as the new shooting core for elves, and while its fewer shots, they’re better shots as well as a much faster and useful (as chaff, as flankers, as war engine hunters?) unit. And a simple swap, with just a little points rejiggering.