The waters of this thread are muddy indeed. That is, though, not because the argument hasn't been made clear, but rather because there are several arguments which have been intermingled variously on the one hand and on the other hand because the debate here is oftentimes a less rational and instead more emotional one.
So, it's imho not only the things you brought onto the table, Evelyn. But to start with the ones you have brought up so far:
From what I can tell, no one involved in this thread has a problem with the statement "slavery is bad".
So, I think that while painting with a broad brush, this might be true, there are actually some people here who would deny that: Not because they personally think of slavery as acceptable, but rather because they
a) think that there is no objective way to ascribe the qualities "good" and "bad" to something and thus it is always relative/subjective/culturally dependent whether it in fact is good or bad.
b) think that categories of "bad" and "good" are nonsensical to begin with (which can be for various reasons like the idea that "good" and "bad" refer to emotive stances rather than something with a propostionally relevant content. So, saying "Salvery is evil" would more correspond to "Yuck! Slavery!" Which isn't really something that has a truth value).
And no has a problem with "Most of the people in New Eden abhor slavery and therefore they would have strong (and negative) feelings about any Ammar they met".
I think here the question is, what 'most people in New Eden' is supposed to mean. There are aruments that the Caldari are kind of 'neutral' in regard to slavery outside their turf and think of it more as ineffective than abhorrent. There are arguments that population wise Empire, Mandate and Kingdom (together with the pirate factions) are 'most people in New Eden'.
I think, though, as you said that both of these questions are not the ones which are really heating the debate here:
The trouble seems to be when someone says, "Slavery is bad, Ammar practice slavery, therefore an Ammar character can only be evil." This is fine from the perspective of an in-game character.
This gets closer to the issue and indeed as most people would say that while in-game that's a position that a char can take, it's not as easily bought into as far as it's an OOC position. Though, here it seems to me that people are agreeing largely on this.
However, it seems (or is perceived ) to be an OOC viewpoint as well, which tacks on another little bit "if you play an Ammar character that is 'good', then you must believe slavery is 'good' in real life". This seems to be the true conflict in this thread.
I think that gets closer to the conflict at hand, but I think it's stating the problem in too wide terms. As many people seem to agree that an Amarr can be good despite being a slaver, it seems that most people agree that the player of an Amarr can be good despite playing an Amarrian who is good
despite being a slaver. It gets tricky here, though.
((though I'll admit that half of players feel defensive based on a statement similar to "you only hate my character because you hate slavery in real life" so perhaps we are all talking about completely different things in nearly the same way)) It seems safe to say that the only real issue people are having with slavery (in-game and out), is the OOC presumptions being placed on themselves for the character they play.
Indeed, this seems to be the issue that people have: When others put OOC presumptions on some players based on how and which chars they play. This isn't merely a question of good/bad though.
Interestingly, no one seems to think it's a problem if someone portrays an Amarr as evil or evil in so far as he is a slaver. The problem really seems to arise at the specific point that someone portrays an Amarr as slaver and as a benign, gracious and friendly in his function as slaver and towards his slaves - as somone who is appearing as a 'good' slaver.
It seems to me that some people claim that one can be a good Amarr despite being a slaver and it's okay to portray this, but on the other hand it is not possible that an Amarr is good - or appears good - in so far as he is a slaver and that thus portraying an Amarr as being a 'good' slaver is somehow problematic. These problems are by those claiming such explicated in three ways, apparently:
1) The player portraying an Amarr as a good slaver and thus slavery as somehow (possibly) good is unethical (bad if not outright evil) and probably 'pro slavery'.
2) The player that is protraying an Amarr as a good slaver does so because he couldn't bear playing a 'proper slaver' (sic: one portrayed as evil in so far as he enslaves people, though having maybe other redeeming qualities). In this case the player is 'doin it wrong', he is somehow failing to play the role he picked.
3) The player is portraying an Amarr as a good slavers is simply 'doin it wrong'. He picked the wrong role or plays the role of a slaver wrongly. He might be a troll.
These explications rest on the assumption that one cannot portray a slaver as being somehow 'good' in his role and function as slaver and is therefore 'doin it wrong' either in representing what a slaver is or in being mistaken in whether slavery is good or bad.
Somehow these people think that a slaver has to abuse his slaves and won't shy away from abusing them in all possible ways. Apparently, for them the question whether slavery is acceptable or not rests on the question whether slavery implicates abuse by necessity and whether one is able to be somehow 'benign', 'gentle' or 'good' in the function of the slaver.
As if, if there is a slaver who doesn't abuse his slaves, who makes sure that slaves benefit from their work and are treated in some way fairly, are well housed and cared for in terms of food, shelter and medical attention, that then they would be compelled to agree that there are good cases of slavery. This idea, though, is wrong. One would merely have to accept that there are better and worse cases slavery and that one slaver may treat his slaves 'good' in relation to other slavers or a possible treatment of slaves that is worse. This, though only means that within slavery there are relatively better or worse cases. Not that suddenly slavery isn't bad in general anymore.
Of course, though, one would suddenly have to do a lot more to show that slavery is bad. One would have to put a lot more effort into building ones arguments against slavery. One would have to put a hell of a lot more thought into it. Suddenly it wouldn't be as easy as "Slavery is abuse is bad!" anymore. Suddenly the work of Bartolomé de Las Casas wasn't something that wasn't really necessary as it was obvious from the beginning that slavery is unethical. Suddenly the better part of the history of mankind would be more than one gigantic case of people just not seeing the obvious truth that slavery is bad or seeing it and doing it anyway. Suddenly the work and effort and sweat and, yes, blood that has been put into bringing it to the fore that slavery is bad makes a lot of sense and is something to be genuinely valued.
But enough of my pleading to see the problem whether slavery is good or bad or neutral as just that: a true and full fledged problem.
I think the real challenge is proving to an audience of players and characters that this humanitarian slaver is a sympathetic character. [...] Some of the best writers in Earth's history have made barbaric characters into sympathetic ones despite the preconceptions of their audience. Part of that involves immersing the audience in their world to aid the reader to understanding their perspective and motivations.[...]
That, exactly. And I take issue with people who are telling me that I am either a) doing it fundamentally wrong or b) am an unethical person if I try myself at doing things that are similar to what 'some of the best writers in Earth's history' have done. I have various reasons for portraying a character that is a
humanitarian slaver and who is not only overall sympathetic but also sympathetic in the way she treats her slaves: next to making a case for taking the
problem whether slavery is good or bad or neutral seriously it's about critique at taking certain of our social institutions as good without second guessing that and provoking thought about how we treat the lower rungs of our societies.