Rb, how much do you ride? I can't keep track of some user names, I thought you were the NYC dude, but I must be wrong.
Seems that you're trying to suss out stuff from asking folks here, but definitely with this one, you've just gotta ride and ride and listen to what your own butt and bits tell you.
for me personally, unless I'm commuting , I wear the same padded bike shorts for any proper rides, and maybe put some thin overshorts on top if I'm doing a bit of mountain biking. Without padding my arse gets sore, simple as that.
I also find regular padded lycra shorts alone to be cooler in really hot weather, but then to be honest, I don't have any good mountainy type shorts that have padding, so I have to double up, which is just plain hotter naturally. Probably less of an issue when cooler.
re "looks", I don't care about riding with "road" shorts, but I certainly don't want to sit on rough things or fall onto stuff with my good (expensive) bike shorts, so another good reason why ill put on thin over shorts on top mountain biking, but for most any riding even on dirt or whatever, bike shorts only are my choice.
For years I've considered trying some good biking regular looking shorts and maybe padded inners, but in the end just don't bother and prefer to use the money for different tires or something else.
good luck