I don't know any of these answers really just writing down my impression on some of them.
Don't remember properly but think they never said it out right he just happens to look like the dad in the flashback Ryner had about his mom and dad and some hints here and there like the things he said.
Well wasn't that random thing Alpha? Also think the random black haired woman is suppose to be his mom.
Not really Milk wanted to know about Rolands darkness and subsequently accepted it. Also they're soldiers, they may not want to go to war but they're aware of what's happening around them with Gastarks invasion be imminent so rather than waiting they went on the offense. Besides they probably talked to Sion before the war just that they didn't include it in the episode, not to mention their faith in Sion.
And think about it those human experiments won't die so that means that there'll be less casualties on their side while they can protect everything that Sion has built up rather than let it all be destroyed when Gastark invades them. So it makes sense that it's the most efficient way to protect Roland with the least casualties on their side.
I don't know if it was the light beast guy didn't look at it properly, anyway I figured the message was about Kiefer hence why he smiled.
Because he's always been up against unfair odds? We've never really seen him one on one with a great magician it's been platoons of soldiers ambushing them, users with heroic relics, undead army that can't die etc. As for why Izuchi probably because he deems it to be the most harmless/less lethal magic he has.
Yes I'd think so