Just a silly question - since you're ignoring the SR aspect of the eldritch blast (ignoring lore / core for practicality) have you considered making it not be simply another evocation? We're loaded with evocation, and it might be fun / good to see conjuration get some focus.
It would create another set of paths / options for past lives - right now this looks to be another class where wizard 1 / sorc 3 is a great past life train - the benefit from cleric PLs is fairly limited in usefulness and could be a fun twist to add into the mix.
If not for each blast, maybe for some / some shapes and/or the pacts? I'm still not sold on "will for acid damage" blatant mechanical oddity - you're trying to force too much difference into the pacts.