And another who gets satisfaction with something directly either hurting or healing. Buff, debuff, action denial aren't really their thing. They want to directly affect HPs. So either some sort of striker role or in-combat healing. It sounds like there's still lots of places they will have fun, right? Any hidden gotchas with that?
The main one is that just wading into combat and attacking multiple times faces rapidly diminishing returns. If you're starting the round next to a foe, it's probably a bad idea to attack three times. You're probably better off doing something like Strike, Raise Shield, and Step back.
There are also quite a few opponents you really don't want to have right next to you at the start of
their turn, because it's fairly common to have absolutely devastating three-action combos. For example, the Dire Wolf can attack you, and if it hits it can automatically Grab you in its jaws as a second action, and then as a third action shake you in its teeth dealing only slightly less damage than a Jaws attack, but automatically hitting (though you do get a basic Fortitude save to reduce the damage). If it needs to spend an action to get close to you, it doesn't get to do its full routine and you and your buddies have a round where you can hopefully Escape before it gets to Worry you again.
Finally, there was a mention about not being able to try disarming a trap without being an Expert and some warnings about if it's worth it to invest only a little in a skill. Could someone expand on that? Do characters need to be focused specialists like in D&D 3.x, or can you be more casual and still have chances to succeed? Is spreading yourself thin to be a jack of all trades viable? And what are "skill feats" - is that just a category of feats that affects skills or something else?
For the important stuff, you need to specialize in skills. There is some lip service paid to the idea of the world being fairly static and so high-level characters will have an easier time with lots of things without specializing. As an example, at about 8th level our party wanted to attack a ship that was anchored in a harbor. Swimming to the ship and climbing it was no big deal, even for the non-athletes in the group (though I think those without Athletics at least had the feat that gives you a proficiency bonus equal to your level even on skills you're Untrained in), because that was just fairly placid water for DC 15 or so.
But for the things that matter, you want to be specialized. Any skill you'd use offensively (e.g. Athletics for various maneuvers like Shove or Trip) will be resisted by one of the opponent's saves, which will be level-appropriate. Hazards generally have very high DCs for their level. Recall Knowledge to figure out an opponent's weaknesses usually uses a DC based on the opponent's level modified by rarity.
Again taking my own experience as an example, my Elemental Sorcerer started out trained in both Nature and Arcana. At 1st level, my Nature skill was +6 (Trained +3, Wis +3) and my Arcana was +4 (Trained +3, Int +1). If I was trying to use Recall Knowledge on a 1st level opponent, the DC would be about 15. So If it's something I could figure out with Nature (e.g. a beast, elemental, fey, plant, or something like that) I would need to roll a 9+, and if it's something that would need Arcana (e.g. a construct or a dragon) I'd need an 11+. That's fairly cool. But then move up to 11th level. Now I am a Master in nature, and I've increased my Wisdom bonus, and I'm pretty sure I have at least a +1 item bonus from something (+2 on plants IIRC), so my Nature skill is +22 (Master +17, Wis +4, Item +1). Meanwhile, I'm still only Trained in Arcana, and my Int remains at +1, so my bonus there is only +14 (Trained +13, Int +1). The DC for a typical level 11 creature is 28 which means I succeed on a 6+. So relatively speaking, pumping a lot of resources into my Nature skill has effectively given me a +3. Meanwhile, on an Arcana-type creature I need to roll a 14+. That's tough. Probably not something I'd spend actions on in combat. My neglect of the skill has given me an effective -3 compared to 1st level.
Now, the DC for identifying say, a wyvern hasn't changed. It's DC 22 (for a level 6 creature) no matter what my level is, so I have objectively become better at Arcana just by leveling up. But the challenges I face rise in difficulty faster than my capabilities unless I keep investing in those specific capabilities.
As for skill feats: Pathfinder 2 has a number of different categories of feats which you get based on your level from various sources. Skill feats is a specific type of General feat (so if you get a General feat you can choose a Skill feat, but not vice versa) that either indicates a specialization of a skill (a bonus in a narrow circumstance) or letting you use the skill in different ways. Normally, you start with one skill feat from your Background, and you get another one at every even level (Rogues and Investigators get one every level). Often, skill feats either require a higher proficiency level or become stronger at higher proficiencies. The skill feats that have been mentioned the most in this thread are Medicine skill feats, because some of them greatly increase the utility of the Treat Wounds usage of Medicine.
At its basic level, Treat Wounds lets you spend 10 minutes on a patient and roll Medicine vs DC 15 to heal 2d8 hp. On a higher proficiency level, you can attempt a higher DC in order to heal more. On a success, you can spend a full hour instead to recover twice that. Treat Wounds has a "cooldown" on any given patient of one hour, which runs parallel to the actual treatment time (so if you start treating a patient at 1 o'clock, you can treat them again at 2 o'clock, not 2:10). There are two main skill feats that make this more useful: Continual Recovery reduces the cooldown to 10 minutes, and Ward Medic lets you treat multiple patients at once (depending on your proficiency level).
Other fun skill feats are Catfall (Acrobatics) which lets you negate a certain amount of falling damage, Magical Crafting (which lets you craft magic items), Intimidating Glare (which lets you avoid language penalties on Intimidation), or Courtly Graces (which lets you use Society instead of Diplomacy to Make an Impression on nobles).
