Your rabbit doesn’t seem unusual. He seems quite normal actually.
It sounds like it was the pet stores fault that he was attacked by the cage mate. He should not have had a cage mate at all, as rabbits will attack each other out of instinct unless the rabbits are bonded, which requires them both to be fixed and a multi-month long process of swapping items, spending time in territory with neither of their scents, etc..
His sudden change of behavior sounds more like it was hormonal, not because he’s a strange rabbit. A neuter helps those behaviors, but keep in mind there is a hormone spike that occurs after a neuter for upwards of 3 months, which means those hormonal behaviors of aggression still linger.
It is not unusual for a rabbit not to seek attention from a human owner, especially since it seems he had a bad, traumatic experience at a pet store. Give it time. Don’t force interaction with him and let him get more comfortable and feel more secure in your home. Some rabbits take months or years to trust their owners. It’s not strange, it’s quite natural because they are prey animals.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.