Ephebopus aren’t the best T for a beginner since they are very fast, very bolty, and can be defensive. If you’re looking for a more beginner-friendly T that exhibits similar fossorial behavior I’d recommend Aphonopelma seemanni
Depends on the person. Like with all species. It can be done.
Usually ppl starting in the hobby want display T's that are visibly often. I assume most won't like that it's fossorial when it comes to rehousings, too.
Aside the above, it's a nice genus and my E. murinus was stubborn, if anything. Never bolted, never threatposed once. She either hid, or played dead and didn't move up to the point where I had to slide the tongs underneath her and move her like that. Temperaments vary though.
It's not even a question of the genus, as a whole, being a fast and mildly defensive one (More 'grumpy' than true defensive in my experience, but anyway).
After all, isn't something exactly unheard that a lot of beginners purchased/purchase the likes of P. murinus as first/second T's.
The main problem, for the majority of beginners, is to provide and mantain the parameters those kind of T's needs: I'm talking about the right balance of substrate's moistness combined with a correct ventilation.
"You" can't keep those into the average "bone dry" set up and done, "you" can't keep those into a sort of 'paludarium' without the correct ventilation either.
Last, with slings, all of the above is in general (for the unexperienced) even more difficult, for that slings are more fragile than their juve/adult counterparts.