Would it harm anything to make all of the missile spells range 40/80, Acc 2? Even Curse-Missile?
I'm thinking no. It slightly nerfs a few (Lightning, with its 50/100 Acc 3, for one) but smoothes it all out in terms of rules since we'll never need to look anything up. Acc 2, 40/80, effects as listed.
You could potentially sweeten up one of the weaker missile spells - like ice dagger - with more Acc. I'm inclined to sweeten that one up with a (2) armor divisor, but whatever, you can note that in the spell description instead of needing a table.
Unless my players have a reasonable objection, I will make this change to the basic Acc and Range of Missile spells for DF Felltower.