Again, this is the heart of the matter. Proficiency takes time and effort and I am not sure it is comparatively worth it.
Proficiency will come naturally. Honestly it's basically the same as 5E but adding level.
I do get being overwhelmed with Traits/Tags, largely because some of them use verbiage that is similar to 5E but not in the same way. I remember looking at the "Concentrate" tag and trying to figure out what it meant, and it wasn't an actual
rule, just something specific things keyed off of: Barbarians while raging can't use any action/feat that has the Concentrate tag, for example. So every tag doesn't necessary denote a rule you need to read, but something a feat or skill might be triggered by. And you don't need to know all those at any given time.
For me, the key was breaking them down into different areas. I would recommend NOT using the Archive for this because, since the Archive has
everything ever printed, it's going to look way more daunting because it's got everything in there. It also mixes in a little bit of old PF2 as well (I was looking at the actions and under "Casting a Spell" it was talking about different components and what traits they add, but traits are just intrinsic to spell so you don't need to worry about knowing that). But start with Action Traits, the ones you see attached to actions: Move, Attack, Manipulate, Concentrate.
Then it was casting things. It's easier now with the Remaster to look at the book since AoN still has problems sorting certain things since when you ask for "All" they really give you
all. But most of those are fairly self-explanatory (Fire, Cold, etc) or fairly simple mechanically (Subtle). Then Armor Traits, then... well, Weapon Traits are arguably the biggest one, since there are ones that are far more important (Agile, Versatile, Deadly, Fatal) compared to others (Backstabber, Forceful, Backswing). You can get away with forgetting the latter, but the former are closer to big effects you'd have to know in D&D.
For me, I can adlib pretty well in the system. I think I do it better than 5E largely because I have a handle on what I'm tossing and what the effect is likely to be. 5E's loose tolerances were good if you wanted to be able to toss stuff at a party and not worry about them dying because the game is overbalanced towards the players after the first few squishy levels. But I always found it rather unsatisfying to have to really create custom enemies and such to make combat
interesting. I'm also someone who was "I wish things were less swingy"... or maybe it's more accurate to say "I wish characters had a bit more niche protection", as it was very difficult to get my players to invest in skills that weren't necessarily to their stat strengths (one of my first modifications was to get around this).
With PF2, I think it requires a bit of rules investment and time, which not everyone has and not everyone should have to give; you have to make decisions about your life and learning a new system is a helluva commitment. But I think it allows you to do something similar to 5E, but in very different ways: with minimal prep (largely knowing your party's level and what the level DC's are, if you want to play that way) you can really easily create situations that give you the sort of challenge you want without having to put a bunch of guesswork into it.
But it's my read that you're more of a "toss it at the wall and see what happens", which isn't necessarily what PF2 is about. There is obviously Prof without LvL, but I think you probably want a more light narrative system in general.
