Not to cause any ruffles, but pfa does exactly what it's suppose to do. Hevucas /skeletal priests/ hevuca high priests these all spam hold spells which are fatal if pfe is not applied and low levels aren't going to have any effective protection measures if you casually nerf it because it supposedly aims more towards balance. There's also the fact of fear aura's, unnatural visages/ horrid visages which will cause fear (acts as a mind effect) which pfe also protects against from with ghosts and other undead.
Clarity is great fro running away from things, but not much else.
Lesser Mind blank is great for combat, but the wizard/sorc needs to be able to prepare it for a group and its not a low level spell.
Mind blank is great, if you have a high enough level caster for it.
The only thing the current pfa spell does at current is mostly protect you from fear auras and such, good, evil, neutral if you use both (which doesn't always work). I don't honestly see how this would unbalance anything, unless the goal is to really have a group of adventurers running for their lives as the first sign of anything and being feared to the point of being stupified.
It would make things increasingly harder for everyone, especially new low leveled characters.
Honestly I would think before any more spell changes were implemented the issues with the current ones would be fixed first. Ie, flame weapon not working on all the weapons, gmw and keen edge occasionally causing breakage with damage on certain things, so on and so forth. (unless for some reason I am the only one who has had the experience of being buffed with gmw/keen/ and flame wep and being stuck some how with a lower to hit and only flame wep dmg working)
Or finishing the crafting systems and removing the items which still have templates out there which don't work. Quarter stave's, whips, platinum, gold, and so on.
There is a great drive to move forward here, and so many great things due to progress that maybe we have all forgotten that in the path left behind there is still rubble from blazing that trail. Heck, if I had the opportunity I would jump on finishing the crafting system. It's progression is pretty straight forward after all and I doubt it is as hard as its been made to seem to work with.
I really think the idea of getting more toward pnp is a great one, but why not fix the broken things before trying to change more?