
I am in awe that you had the will and self-control not to say "You know, you are a pathetic human being." Wow. I don't think I could have withstood the test.
I agree but their behavior (Josh's, Oldest's Youngest's, Kay's, everyone else's difficult kids) does not give them the right to act and/or speak like boors. I could care less about how much Youngest / Josh / Kay / etc. may be hurting inside; they cannot speak to Mrs. 200Meters & I / Beta / BusynMember / etc. like they have sometimes.
Yup. 
Yup. 
Why are they unable to do better than they're doing? I'll speak to Oldest & Youngest. Apart from their ADD/ADHD (which can't become the default excuse / justification for the yawning gap between their appetites and the state of their teeth, figuratively speaking), it's because they're some or all of the following in varying degrees: Lazy, self-centered, self-indulgent and shortsighted.
Agreed. But...
When we are treated so offensively & so hurtfully, it is hard to be empathetic. I am no glutton for abuse and tend to lose interest.

I dunno about the adoption-genetics thing. I've got some pretty messed up stuff in my genetic history which, thank G-d, I cannot pass on to Oldest & Youngest. Who knows, if they had been our biological kids, they might have turned out worse.
Ditto. Our flat is awash in books, all of them ours.
Ahem

Ditto x 2