RE: when to stop trying
I would have any guy who can tie his shoes, chew gum and see well enough to drive to the field solo'd in a day............ but not with some lead sled, 6.5 pound ARF "trainer".
That kind of plane can come later. It's too much, too soon for a lot of guys and when disaster strikes it's too bitter of a pill to swallow.
Some guys need to start out with single digit wing loadings and stay with those type of planes until they can land them on a dime, then "move up" in wing loading gradually......if going to heavier models is the plan.