Don't have time to answer all that, but one thing - who is Ruby?
And second - if you are basing only on manga.. then first read LN. Then, and only then, we can talk seriously.
Like, seriously.
Rudeus Greyrat, son of swordsman Paul and healer Zenith - aka the main character. Yes, I messed up the spelling of his nick name. Thought it be quite clear who we were talking about since there aren't that many prominent pedophiles in the manga. There might be in the LN's, but I wouldn't know.
And second - if you are basing only on manga.. then first read LN. Then, and only then, we can talk seriously.
Like, seriously.
Yes I'm talking about the manga more or less exclusively since this is mangadex's forum where we talk about the manga's that get uploaded to their site. Not that the anime is doing the source material any favors either. And no, I won't humor your request for me to read the LN's when you can't even bother to take the time to answer points raised in my first post.
Also, you are totally forgeting, that manga skipped one important arc.. but then.. if you did not read LN, you may not know that.
If the manga has left things out, it's a bad/subpar adaptation which yet another thing worth criticizing.
And, well, "selling your kids for [thing]" - it wasn't wrong, not so long time ago. It become wrong recently.
Remember that slavery exist, in Rudeus new world, and in ours - even if it is now hidden in ours.
Now we think it is wrong. But ask someone from 2-3 hundres years ago - you sure what they will answer you? What about thousand years? Still sure?
Slavery is wrong now. It may become "good" in future. Saying something is "good" or "bad" is very cultural thing.
I'm going to take this as a lukewarm piss attempt at trolling. There were people who lived in the time when slavery was legal that objected to it, both on legal, moral, and ethical grounds. It's how it got abolished and made illegal in the first place. I'm going to give you some serious, heavy duty benefit of the doubt and assume you already knew that. If not, read up on some history or at the very least read
Uncle Tom's Cabin. Written in 1852, it's a piece of anti-slavery literature.