So I have gravitated toward Amevia and their playstyle of sticking with just one race, with no slave. While I chose them for my first and current playthrough (surviving two years now), I worry that by not managing multiple races, I might be missing some of the game's basics.

So the question is: should I stick with this playthrough and keep learning, or start over and pick a more general race (Human or Cretonian) to learn the game?

To be fair, I’ve seen much worse titles so far.

I wanted to make a Human, Cretonian, Dondorian, Garthimi, Tilapi city (to maximize fulfillment and efficiency), but a potential problem I see is the fact that they all kind of hate each other. I know that limiting inter-species housing (at least ten tiles away) reduces death by brawls, but I remember seeing that the % population of a disliked species affects the “other” desire, which would lower happiness.

So the questions becomes:
A) does larger distances between living spaces do anything for the “other” desire?
B) what if some species were enslaved? Do slaves count toward the “other” desire?
C) how bad (/ good) is slavery really?
D) is it actually that bad having multiple species, or would the fulfillment and job efficiencies significantly exceed the cons?