A few quick spellcasting fixes that SHOULD go into U11.
1) Extend should apply to Summons. No reason not to. It's just annoying, would provide a very small amount of utility back after you gutted it from offensive spells, and if you can keep a pet alive for 20 minutes then there's no reason not to allow it. Frankly, Extend could make the summons permanent and it wouldn't be overpowered.
2) Extend should also apply to Divine Might. Ditto the "giving a reason to use extend" as above. Sure, at 2 minutes regen + 2 minutes duration you could keep it going indefinitely as a Radiant Servant IF YOU NEVER USE YOUR AURA OR BURSTS TO HEAL. Since people DO use aura and bursts, I don't really see the problem. But if it just totally freaks you out, make it 1 min, 45 seconds. 1 Minute duration on DM is just too little to bother with. Without this adjustment I'm probably ditching Divine Might as I never seem to be able to justify using it for my 2 pts of damage for a measly 1 minute.
3) Again.. Radiant Burst should work, centered on you, regardless of who/what you have selected. A quick fix would be to save the previous selection, select the caster, Burst, restore the selection.