Yeah, I don't recommend having new players make high level casters to start out with. PF2 spells generally do a good job of saying what they do, but it takes a long time to read through them and make sure that you understand all of the traits and specific terminology. But that was true in PF1 as well.
One issue brought up that I think is interesting is whether or not it is easy to trap yourself in a build that has no where to go as you level up in play. I think the theory crafter answer is absolutely, but I am wondering, if in play, it will become apparent enough when you reach those very dead levels for certain feats, or that your proficiency is falling so far behind that you are starting to get frustrated, that you will be able to train out of it organically enough to feel satisfied. That will largely depend upon GMs and will probably take months before actually new players reach those points, but they are things I would love for GMs and board followers to pay attention to and report back on.
I think low level casters are more problematic than high. Take the Demonic Sorcerer with Fear as a 1st Level spell. A new player might spend two actions casting it where an experienced player will use Demoralize with one action without using up a spell slot, and save the spell slot for heal or magic weapon. Casting the granted spell is a trap.
Retraining prevents traps to some extent, but unless you have a friendly GM, the granted spells of your bloodline are going to follow you all the way up.