Someone using Scout as an exploration activity is better than Incredible Initiative because it applies to the whole party and doesn't stack, and there's a feat that brings that to +2 that the scouter can take. One person can take that and the whole party effectively gains the benefit.
Are you the party healer because you're using Battle Medicine? If so, Robust Health is excellent. +level healing and you're only immune to Battle Medicine for an hour so you can do it on yourself more times per day. With a BM healer, everyone in the party should consider taking this.
Otherwise, Toughness and Fleet are both good. I prefer Fleet first because 30' is a drastic speed up over 25' due to difficult terrain: that means 15' instead of 10' (and 10' vs 5' in Greater Difficult Terrain). But you're not going wrong with either choice. :)
Quick question: What did you take as your general feat at 3rd level?
Personally, in order of priority, I generally take Fleet, Toughness, and Incredible Initiative for most characters (at 3rd, 7th, and 11th; humans with the versatile heritage and/or General Training, or characters that gain one of those three feats elsewhere, can switch things up a bit with Ancestral Paragon, Shield Block, etc. depending on what I want the character to do). Speed increases are hard to come by, the +1 hp per level from Toughness is useful after advancing beyond lower levels, and the +2 on all initiative checks from Incredible Initiative is very good.
I also almost always take Canny Acumen at 15th or 19th level on a saving throw that doesn't gain Master proficiency from the class (as Canny Acumen increases that save to Master after 17th level).
If you want a bit of recall knowledge as a side gig you can take untrained improv. It gives you level to proficiency in all untrained rolls, which includes recalling knowledge with lores - which gives you a DC reduction. As an INT class you’re in a good position to make use of it. Not as effective as a true RK build but hey it’s cheap.
I do use Battle medicine but I also have elixirs I can QA and some more permanent ones, and I make a few as my dailies. I have 6x Lesser Elixirs of Life and 3x Lesser Healing Pots at this moment. The rest of my group are a psychic, a monk and a thaumaturge. The thaumaturge has a hand crossbow so I bought Life Shot ammo to have backup healing, and both them and the monk buy healing potions when they can. The psychic is a talking cat so they can't really do much in the way of healing. A few sessions ago my GM was gracious enough to allow them to paw out an Elixir of Life out of my backpack and somehow get it into my mouth so we wouldn't have to re-roll our characters, maybe...
Oof. Your party needs a front line character. :)
Robust Health would definitely be good here, as would Toughness and Fleet. All good choices.
Do you have a suggestion for one? I was considering Risky Surgery or maybe Read Lips. My group just got to Oppara and we're a halfling(me), Orc, talking cat and a human, and my GM has told us that the people are kinda racist towards non-humans. Reading lips could be useful in obtaining information as it's all our first time in the city and we're trying to look for work.
Risky Surgery is one of the worst medicine feats IMO. it only works on Treat Wounds and it adds a small amount of healing that doesn't scale (plus 2d8 more if it manages to flip a success into a critical success but that's not happening a ton). This gets less and less meaningful as you level and you're healing for more per action.
If you roll poorly it can actually reduce the amount of healing done, and the worst case scenario is you do Treat Wounds on someone unconscious at 0 HP, fail, and now they're suddenly Dying 1.
Since you have Assurance, the +2 bonus is often useless, since Treat Wounds is a great time to use Assurance.
I have characters with literally 6 skill feats in Medicine (some via Medic Archetype) and Risky Surgery is not one of them.
In terms of feats.. Battle Medicine/Continual Recovery/Ward Medic/Assurance are the big four Medicine feats until you're Master/Legendary or have Medic Dedication, which opens up more options. Robust Recovery is good if you're dealing with a lot of poison/disease (but only if its coming up a lot, like it would be amazing in Spore War).
I will say that in a 3 person party with an Alchemist, Ward Medic is less useful than in a larger party. You have downtime healing alchemy and versatile vials, so you just don't need that the way someone in a 5-6 character party does. It's proven clutch for me in PFS when time was a factor. It's not bad, but's not as good as it is in a bigger party.
Otherwise, take a look at another skill. If your GM is running in a way where Read Lips matters, it could definitely be useful.
I unfortunately took Assurance because I thought it would be good to have a guaranteed Treat Wounds. I have now realized that it was a waste of a feat and plan on retraining it when my group has some downtime. I think I had considered Fleet at 6 but then I saw Continual Recovery and decided to get that instead.
Assurance is awesome for Medicine though. Battle Medicine is something where you often cannot afford to fail, and a crit failure can literally kill a player by doing damage when they're already dying.
Medicine has a LOT of simple DCs which means Assurance can beat them and deliver reliable, no failure healing. When you can only do the action once per day/hour, failing is a massive opportunity cost. Plus at level 6 you're doing the DC 20 BM/Treat Wounds without failure, and at level 14 the DC 30. And it doesn't care about your Wisdom, which likely isn't maxed since you're an Alchemist.
There's a ton to love there.