I am curious what find intimidating about adapting PF2 to other setting.
I ran PF2 in a homebrew setting and ran into a few issues. A lot of these are due to the nature of my setting, so others may have different or less severe experiences than I did.
My homebrew setting does not have any of the common D&D ancestries. The two closest (elven and yuma, which are humans renamed to avoid confusion by players) are still different enough that I did not want to use human as written in the book. I wanted humans to be another kind of monster (setting eschews humanocentrism). That meant I had to devise new ancestries for my six core ancestries, and I had to create ancestry feats for them. There were far fewer ancestries at the time, so there were fewer feats to repurpose or use as a benchmark when designing my own. If you can get by with the core races or taking some of the published ones and tweaking them, that will make things a lot easier.
A cleric gets a lot of functionality from their deity in PF2. There are still domains, but every deity has edicts and anathema. The latter is important because clerics are obligated to follow it. My setting has religion but no actual deities (powerful creatures that are worshiped don’t grant powers or anything). I also don’t like the way D&D has traditionally approached religion, so that meant I had to come up with a bunch of cleric stuff to replace the core deities. That never really happened except in the case of one player, and (at the time) it was fortuitous that I could use Sarenrae as an angel that was worshiped. Most people won’t have the problems I did, especially if they can reflavor the core deities or adapt them to other settings that work similarly.
I don’t like the champion class. I thought the paladin in PF1 was more interesting because its powers came from belief in its righteousness than being an emissary of a deity. That meant you could have thematically interesting situations like a paladin of Asmodeus. That’s not the case nor possible in PF2. I made some attempts to hack up the champion to be oath-based, but if I ran PF2 again, I’d just ban the class. It was a lot of effort, and it worked really poorly with the tools at the time (Hero Lab Online) because its support for homebrew was pretty poor (especially compared to Hero Lab Classic). This is related to the above in that if you have a more traditional D&D approach to religion/deities, the champion is probably fine.
A more practical issue is the PF1 Player’s Companion line got combined with the Campaign Setting line in PF2, so a lot of new material is published in the Lost Omens line. If you want to use it, you’ll have to adapt some of it to your setting. I categorically disallowed it because I was not willing to do that work (on top of everything else). I’d also add I liked some aspects of Golarion more before it was changed in PF2. I actually liked having a functioning Evil civilization. I think that’s more interesting than where things seemed to be heading towards the end of PF1 and into PF2. I also liked that Good people and factions did some seemingly awful things, and those were not necessarily against their alignments. I think alignment is more interesting when it’s not just the clearly good versus the clearly bad.