The way these two spells work always bothered me. Here's a suggestion/fix.
1 Negative energy ray:
Damage is too low to be useful, especially given how many evocation spells were buffed. Why cast this when Horikazaul's Boom can do double the damage, deafens, and uses a will save? Your cantrips will out-damage this easily and with no save at all.
2 Ray of enfeeblement
It can do a lot of strength damage at high levels, but it's a fortitude save on a circle 1 spell, the DC will always be too low. Even at low levels, for the typical "Save or suck" spell, the "Suck" part isn't any good either.
An idea: Maybe merge these two spells into one? So you can do some damage and sometimes zap enemy strength when they roll a one on their save. Necromancers get this for free, so it might be a funny thing to use sometimes.
Negative Ray of Enfeeblement anyone?