Interface Zero, a third party supplement, has a medic class that you might want to look into. It's a cyberpunk world without all the magic of Starfinder, but you can add magic in easily enough. I recommend it because in the NPC's section there is an android medic called the"Medi Andi" which was a corporations attempt at creating a medical assistant and your concept reminded me of it.
I agree about the third party products. One you might want to look at is Interface Zero. It'a non-magical cyberpunk version of Starfinder. It has a number of races similar to what op posted. It does have a psionic class and archetype, but those can be ignored if you want. It could make for a more "science" and less "fantasy" version of Starfinder.
I would like to see a Player Companion about constructs. I'd specifically like to see some more about animated objects and some new construction point options. Also, more on the Craft Robot feat (in the last volume of the Iron Gods A.P.), for example how much does it cost to add some of the various options mentioned to robots- does it cost extra to add a self destruct option to a robot or does it increase the CR. Something along those lines. Maybe we could get a new Archetype that focuses on building constructs. I'm aware of some third party suplements and the notes in Ultimate Magic but I'd like to see that expanded into something more.
I've got a few questions,sorry if they've already been answered.
First: Epic DR vs. Mythic, Does being mythic mean you can ignore Epic DR or do you still need a +6 or better weapon.
Second: Legendary Items, If you take the upgradable ability on a weapon or armor can you only increase it by +1 or can you add special abilities to it. For example: If I have a +1 sword can I add the flaming special ability or can I only make it a +2 sword.
Third: Mythic Skill Focus, It says I can take 10 or 20 anytime even when rushed of threatened, so if I have Mythic Skill Focus (Diplomacy) can I take 20 at the start or even in the middle of a fight and try to convince the enemy to be my friend. Also, I assume that you still get the bonus from regular skill focus (+3 or +6 to skill if you have enough ranks).
Overall I like this book but I do have a few issues. For one thing the book seems like it should have been longer, Legendary items should have gotten a whole chapter with example items and some more abilities since most of the abilities can only be taken for minor or major artifacts. It would have been nice to see some more paths or at least some more universal abilities. I do like some of the universal abilities and think they might be good to use as rewards above and beyond the path system. A GM might decide that you can't take divine source as a path ability, you have to earn it by completing a special trial. If you complete the trial you get the ability for free, of course it would be a very difficult trial. If you want to improve it you have to complete additional trials. This allows PC's to play their characters but allows for some story elements as well. This would be good way for PC's to get legendary items and makes it more in keeping with the story.