Darren Daz Cox asks "What would be the main factors that your group of colonists must share in order to have a stable colony?"

The verb "be" asks of the metaphysical - what exists ... such cannot be "known" other than by hypothetical model (according to current science).

So I would rephrase the question...
What do (I, you, he, she, etc.) think, guess, hypothesize, etc. ... "ought to be included" (instead of "share") ... in order to enhance "stability"? ...

By "stable" does the source "mean" "survivablity"?

... in the face of unknown conditions...

If there is no possibility of return communication, of what utility to those who remain behind is any answer to the question possible?

Consequently, the sole criteria that can be applied is whatever those who want to go decide they need as a group, or individually as separate groups.

Since I'm not going, I needn't answer the question for myself.