Did you know that every cocoon/egg has 2 armour, while Lurker egg has 1 and for whatever reason the Ravager egg has 5 armour? Increasing the consistency of the game and giving these two units 2 armour eggs, would actually really help the protoss Phoenix opener, since Phoenix do no damage to Ravager eggs currently.
Other significant changes would involve removing Corrosive Bile damage on structures or increasing the Ravager morph time.
Overcharge +1 range would be another change that would really bring Protoss back in full force, since it heavily nerfs Queen/Ravager timings, while also nerfing the Liberator, this could mean we don't have to go through with the radius nerf.
The +damage vs light on Liberator (Nerf to anything not Light) Anti Air attack could be interesting, this would allow for the change to the Thor where it deals flat damage across the board (AoE) to exist, since they no longer overlap. Though scaling up the damage of the Thor to that of it's current +vs light damage, would probably be a little too strong (As seen on the Balance Test Map.)