What I strongly suspect :
5) On unexplored island, you much more likely to find advanced tribes. Probably that huts on the coast are more favorable too.
6) You don’t get nomads after a certain period or tech. Is it Explosives. They are more likely on some terrains than others. Forest should be the best.
What I don’t know but would like to !
Huts outcome might depend, but I have no proof of it :
d) on the direction from which you open them
e) on the characteristics (civilized/militaristic expansionist/perfectionist) of the civ you are playing with
f) on its distance from the nearest city
g) on the direction of the nearest city or capitol
h) on the nature of the units opening them (explorers, diplos, 1 move, 2 move units).
i) on the number of squares explored around the hut before a unit moves in.
j) the positions on the powegraph (the weaker you are, the more favorable).
k) the type of governement
l) if the unit is veteran or not
m) what was open in the last hut
Any opinion, any other idea. Anything that I have forgotten.
I shall start my testing !