The bcurious can be used anywhere you may want surface vibrations, just not for insertion. It's not made in a way that insertion is really even possible, other than perhaps just the tip.
I haven't run it completely out yet to see the exact time the charge lasts but I will say I've gotten three twenty to thirty minute uses out of mine on a charge. So, at least an hour or better.
It charges in two hours and most rechargeable toys last about two hours so I'd say this is likely the same.
It's very powerful, more so than my other rechargeable toys, and is so quiet you can barely hear it. It's not as powerful as a plug in massager, of course, but it's certainly as powerful as a very good bullet vibe.
Hope that helps!