Sure is.
You are required to provide a safe and stable living environment for children. Being homeless does not qualify as either, and the party in question would most likely have the children removed.
There are no laws against it.
yes
It all depends on the laws of where you live.
Not if the live in Norway.
No, a 19 year old boy is not a boy and at the age of 18 he is no longer considered a minor, but a man and if he dated an 11 year old girl her parents could press Statutory Rape charges against him which he well would deserve.
Not unless she's his legal guardian.
Possibly it depends on where you live and if the parents allow it.
If you live in the US it is.
hell yeah live it up
No, it's statutory rape committed against the boy.
it isn't illegal to date, but it is illegal to have sexual intercourse.
There could be charges against the adult. The boy shouldn't be an issue.