Whitehawk are a weird mix. Before the money came flowing in they had a small core of fans who would probably have fit that description, but now there’s a new breed who are more typical Brighton/Hove in outlook.
FCUM have internal politics to worry about, legacy of Andy Walsh and his group at the top of the club. It doesn’t seem a particularly happy place to be, but their politics seem far more focused around the purity of football than anything else - I’m not aware they’ve ever been involved beyond the level of a normal footbal club outside the Supporter’s Direct movement.
Lewes are probably another one for your “not” list - first club to pay women and men equally, quite a hipstery vibe.
As for avoid clubs - I’ve always found Wealdstone fans to have a nasty edge to them, but some people like the atmosphere that brings. Online they will call out obvious racism where they see/hear it, but there’s also a lot of talk about how Harrow’s changed and immigration being to blame for some of their club’s woes in the 90s and early 00s and they get involved in a disproportionate amount of crowd trouble.
Billericay I would avoid mainly because of the Tamplin circus, Boreham Wood have a bunch of right-wing twats who turn out for big games, but they’re fine for run of the mill ones and there’s a westcountry club whose name escapes me that didn’t impress our fans at all this season.
Worth saying though, in the main fan bases tend to be pretty apolitical - even if individuals bring their politics with them, in most cases they’re individuals either on the left or right, and most clubs from Step 2 down tend to be pretty welcoming and regardless of the politics of their area.