Islam-QA is quite a reliable site, yes, I learned a lot from that site, not to say it is infallible (obviously) but you get the point, a lot of what they say is not exactly a majority but it is what a lot of scholars say and I've seen a lot of what they say to be in disagreement with what a lot of other scholars but that's not the point.

The second question, I can't answer, I'm sorry.

For the third, I guess you can say that, yeah, I explained to you in the other thread where the posts got deleted but anyway, what you said is right, slavery isn't something Muslims should be apologetic about.