Most people won't give loans out to people who are suspected of going to gamble with it and quite rightly as you're almost certain to lose it, though I don't doubt some people take loans out under a different story and then gamble with it anyway.
Most smaller loans (less the .1 or so) are almost certainly going to be for gambling, (what else could they be for?) I don't think lenders particularly care though as long as they are sufficiently protected with collateral.
Yes. But those who gamble are obviously never gonna use altcoins as collateral