There is no manual for FotR

Alright, thanks. So uh, there isn't any readme or wiki or resource where I can read about the mechanics?
E.g. I see that the CSI can get "influence" from banking clans, what's the point of that and how does it work? Also the era system, how does one progress through it? Killing the CIS leader?

Things are documented ingame rather than in an outside manual or wiki. If you read the government tab, it tells you what influence does with the subfaction and how much you have.

Eras and events within eras similarly get explained within the story tab.

Both of these things, along with various other information, are available from on the galactic view by using the buttons on the left side of the screen.