Welcome!

Did they vet mean to wait for behavioral changes because that’s usually the time they hit puberty and are ready to be neutered, or did he mean you don’t have to neuter at all if he behaves well? Generally we recommend to always spay/neuter. With females it’s 100% necessary because they will most likely get cancer if not spayed (how sure are you that he’s a male? Young babies like this are very difficult to sex correctly, even for a vet.) Males don’t have those health concerns, but neutering helps a lot with potty training and undesirable behaviors. Even if he doesn’t give you trouble, it’s still a good idea to neuter. Males are slaves to their urge to procreate, taking that away will enable him to relax and enjoy life and your company without stressing and feeling “unfulfilled”

You’re doing a great job teaching your boys how to interact with the bun! You’re already doing exactly what would be recommended.

The chewing and peeing is normal for a baby. Once he’s neutered litter training should go a lot better.

He’s a cutie! Where did you get him?

Sounds like this vet might not be very bunny savvy and doubts his own skills. Sadly a lot of vets call themselves exotic vets but really don’t know much about rabbits and their care. There is always a risk with anesthesia, but if the vet knows what he’s doing then rabbits aren’t more at risk than any other animal. Maybe you should look around and for a different exotics vet in your area.

Here is a list of vets provided by the house rabbit society: http://rabbit.org/vet-listings/

On the same page is a link with questions you can ask them to see if they know enough about rabbits.