I really can't see how some people are so high on Bane unless it is as an end of the bench emergency combo-G/floor-spacer who you can count on being in the right position defensively. Some have him in the top 25 on their big board which is INSANE.
Yes, he can shoot. He has good defensive positioning OFF-BALL. On-ball, he is a liability. He just lacks the length and athleticism and I don't think his IQ makes up for that big of a gap.
Offensively, besides the shooting, the passing is there, but he lacks any real burst and cutting ability to get into paint consistently. Watching Bane turn into a drive is like watching an 18-wheeler try and make a turn. See this @3:30 in video below (see spoiler). Overall, he's kind of a stiff athlete. Not much fluidity. He's definitely not capable of guarding most NBA-level 2s on-ball, IMO.
Overall, if I'm looking for a reliable emergency ball-handler/floor-spacer in the late 2nd round, Bane is probably my guy. I can't see him going any higher than 48-ish.
Probably no convincing you at this point, but I think you are focusing way too much on the negatives with Bane.
Removing the length/finishing/lateral quickness issues (and those are legitimate), you have:
-Arguably the best overall shooter in the class, considering shot versatility profile. Elite movement shooter, great pull-up, great C&S, etc.
-A more than capable ancillary playmaker out of PnR, a very decisive passer.
-A highly intelligent and communicative team defender, one of the best off-ball defenders in this class. Pristine rotations, switchability, disruptive in passing lanes.
-A player with impeccable footwork.
-A 22 year old, 6'5" wing with a rumored standing reach of 8'4" and a 41" max vertical, with an NBA-ready body.
It's a copycat league, and teams are going to try to replicate the Bucks' drop coverage which encourages funneling players from the perimeter to the paint, where they meet your rim-protector. Just an example, but this mitigates the importance of on-ball defense, and amplifies the importance of team defense, where Bane flourishes.
Drafting that guy Top-25 is not insane at all, IMO. Having a 36 spot difference in ranking between Nesmith and Bane sounds more insane to me than that.