Q1: The Rules page at http://www.swcombine.com/rules/?Creatures, under Creature_Spawning, says:
Creatures will only spawn on planets where there are no characters, vehicles, ships, or other creatures except the character and their party.
I'm guessing that should either be "planetary terrain square" or simply "terrain square," yes?
Q2: Are the spawning rates as listed on http://www.swcombine.com/rules/?Planetary_Grids correct? Meaning, the Forest rate is 15%, Grassland is 12%, Jungle 10% and so on?
Q3: Is this equation for finding spawned creatures, correctly written:
Chance of finding = ( 1 + Stealth (Perception/30+0.05) ) * Terrain Creature Probability
Meaning, if a character had a Perception of 4 and a Stealth of 4, then the percentage chance of finding a spawned creature in a Forest terrain square would be:
(1 +4 (4/30 +0.05) * 15% = 1 + 4 (0.133 + 0.05) * 15% = 5.138 x 15% = 77.07%, or is it 0.7707% ?
The difference is, whether you take the total (5.138 x 15) and assign a percentage to it, or if you multiply the first half of the equation, 5.138, by 15%, which gives you the lower number.
Q4: What is this spawning equation applied to? Is it the possibility of finding one or more creature groups per entire terrain square, or of finding a group per individual section of a 20 x 20 terrain area you search in?
Q2: One would have to assume
Q3: It would be multiplied in that example by .15, but that final number is a percentage in decimal form, so it's still 77%
Q4: I think it's for the creature spawning somewhere in the terrain square, seems to make the most amount of sense
I can see the need to remove creatures once you leave a 22x22 square, for the very reasons you state. And since it appears that your NPCs stop following you when you're more than a square away, I could see the creatures being "retired" when you leave the square.
I'll post back here if anything unusual happens with creatures in my wanderings.
"When all is said and done, there's nothing left to say or do."