Although I'm somewhat neutral on server stuff, something just doesn't sit well with me in granting Drivers the permission to still redirect and warn.
Drivers are auth in other places that serve as high ambassadors, so to speak, on the server. As for their role in server moderation, being a guide for new members is what they should be doing; they should probably even be among the first to welcome new members to the server alongside our more emphatic veterans and guide them along the "path", whatever that path is.
However, that is IMO where their moderative authority should end. We've got more than enough higher auth on to take care of that stuff at all times of the day.
/kick and /redirect are essentially the same; if one user removal power is removed from Drivers then the other should be as well.
/warn would be alright, as it would help Drivers fulfill their perceived roles on the server as role models for the rest of the community.
TL;DR: Take away /kick and /redirect from Drivers, keep /warn unless for some strange reason an abuse case pops up.