Thanks. Yes, I had checked those. While helpful about tribe fame in general, I could not find much information about the magnitudes of various changes. This is where I got my tentative answer of 10% to Q2. However, nothing is even mentioned in the wiki articles about primary downgrades or collateral downgrades that occur as a result of doing missions.
The focus of the wiki articles is about how to gain fame with a single tribe, mostly ignoring any ill effects that might have on related tribes/civs.
The focus of the wiki articles is about how to gain fame with a single tribe, mostly ignoring any ill effects that might have on related tribes/civs.