Don't go thinking that the Gallente are all sweetness and light, check out the Two Deaths chronicle on EVElopedia

No not really. The Federation is filled with drugs, crime, and racism.
They also attacked the Caldari for seceding for ~100 years. The only reason they stopped attacking the Caldari, was because the Amarr made contact with the Gallente. You see, the Caldari wanted peace, and the Gallente knew they couldn't fight a war on two fronts, so they made peace with the Caldari and turned the Matari against the Amarr to weaken them, because they knew they also couldn't take on the Amarr by them selves.

Basically, Gallente and Caldari were friends, until Gallente started being a bad friend, and Caldari wanted out of the relationship. Gallente then bullied Caldari for not being their friend, until big strong Amarr showed up and scared Gallente, who whispered lies into the ears of Amarr's friend Matari, and turned them against one another. The Gallente are the truly evil ones IMHO.

This is exactly what I've been telling everyone! The Gallente are my most disliked faction because they are the great manipulators and starter of wars. Had the Gallente just accepted that the Caldari wished to part from the Federation, then Caldari State would have lived in peace with no war and the Minmatar would of never turned on the Amarr, who both would of also continued to live on in peace. But no, the Gallente can't handle losing such a large nation from their Federation so start war with them, then use the Minmatar as tools when things start to look grim.

Do you not realize that the Gallente Federation also imposes it's ideology on others? The Caldari culture is focused around everyone serving eachother, working for the greater good of the whole and not the individual. This is in stark contrast to the Gallente who believe in individual values instead. Now there was nothing wrong with either civilization, both were plenty happy with their lives, but the Gallente decided to try and end that culture of the Caldari State and that's part of why tensions rose between the two in the first place.

You do know that as of this very moment, the Caldari are still officially members of the Gallente Federation?

The term "Minmatar Scum" as used by the more aggressive sects of Amarrian loyalists actually refers to the renegade agent of corporations supporting the separatist agenda. The common Matari people who do not fight are the people we would welcome with open arms.

I further the question, how are current Minmatar "slaves" repressed?

I don't find it oppressive because I look at what Amarr slavery has brought to other races like the Khanid and Ni-Kunni, as well as what it's brought to loyal Minmatar, and it's been nothing but vastly improved standard of living. I mean, I'm sorry if I don't find that oppressing.

From my perspective, the only thing people find oppressive about it is they see the word "slavery" and equate it to 17th/18th century slavery on Earth where it was entirely taking advantage of other races for labor and mistreating them and so on, which is not at all the case in Amarr slavery. I have yet to hear an argument that gives any good support, with references and sources, that goes against this claim.