I think the danger is overhyped especially with teh current lipos. The older ones were much more volatile and could cause probs. I've seen them explode on impact in a elec plane crash. They don't do that anymore.
If you use a charger with a lipo charge routine and balance cells while charging and discharging, treat hem with teh care and respect they need, you'll likely never have a prob.
Your radio quest - yes, it should run more than one RC with same radio by just using another rx (compatible) in diff RCs. I run about 2 dozen diff RC models using 2 diff radios - mine is all FM since I got started some time ago before 2.4 was even mentioned. It should work the same way though.