For the balance and the logic of it, i think we should be able to loose social points, if tagged "bad boy" or "incompetent PI". It's logical to loose our social credit while falsly accusing people or being caught while committing various crimes. Here is a few iterations i think of :
_ Being caught / sent to hospital by enforcers with a SP loss depending on how high was your current fine
_ Failing at the resolve of a case and accusing the wrong person should also lower our SP
_ Engaging conversations with people while you stink the sewers should lowers it a bit too. "Be clean or stay in the sewers, boy !" (except maybe for very lowlife people who stinks too)
I guess there are many more exemples and possibilities. I would also tend to think that the stash of SP when lowering should strip us from our current social rank (and it's benefit) when reaching the rank below. It may be reasonable to even think that some appartments should be tied to social tiers, and therefor you could be thrown out of your middleclass rental to land in the fathoms for being bad investigator or causing too much chaos in the city.
Indirectly related to this, i think the side jobs (found in bars, restaurants and city hall) should be also scaling with the social rank. You would get poor paying jobs at the bottom of the pyramid and probably a lot more of "thugs/shaded contracts" like the vandalism and humiliations jobs (but not only, there should be at least some time to time a photo job or something like that).
For the higher social ranks, you would access corporate contracts, like the industrial spying / stealing, high risks filatures (maybe involving some factions of the game) and with the best rewards
My point being social rank is everything in the dystopia of SoD. The game mechanic should insist on that, and constantly remind us that we are only the product of our success or failure.