It's one of Trek's bad production decisions: the idea that if anyone out there was going to be a good guy, then naturally they'd be part of the Federation. It's fine for the Federation to be the United States Writ Large, but its existence doesn't mean that the United Kingdom, France, and Brazil wouldn't also exist.Well, it's not like they have a lot of options. Consider the powers that surround them -- the Klingon Empire, the Romulan Star Empire, the Cardassian Union, the Ferengi Alliance, the Tzenkethi Coalition, the Breen Confederacy, the Gorn Hegemony, the Tholian Assembly, the Talarian Republic. Frankly, the Federation doesn't have a lot of nice folks to make friends with -- the closest would be the Ferengi Alliance.
I can't tell --- I don't have the direct information --- but I have the sense that the Ferengi Alliance was originally-in-1987 conceived as being a sort of parody of the original Federation. The dropped hints about it being explicitly interventionist and viewing the Prime Directive as destroying opportunities for everyone involved gave me that strongest hint. So in that regard the `Humanization' of the Ferengi as it actually worked out would be also the discovery that they weren't so different to start. (Apart from not being a multi-species polity like the Federation was.)
) so the public wouldn't get their moral outrage up and running, and the planet was a Maquis base, so the Federation don't shed any tears over its loss. Which is hard to fathom, really - I realise Class M planets are rather stupidly easy to come by on Star Trek but it seems a bit much to just overlook unleashing a wmd on one out of, essentially, angry revenge.
). Cardassia itself would probably have to be left alone, for the simple reason that it's their homeworld and they need that to rebuild their civilization (if it wasn't too badly decimated by the Dominion already, another thing that's kind of left up in the air).