I wouldn’t try to do any bonding until Muffin has been spayed. She could very well be the reason Alfie and Oscar don’t get along. Having an intact rabbit in the group can trigger aggressive behavior from the others even though they are fixed. Hormones make rabbits unpredictable, one minute everything could be fine, the next you could have a nasty fight on your hands.
I understand that you are worried about the spay, but if you have an experienced, rabbit savvy vet, everything should be fine. Think about it this way, if you leave her intact, the odds of something going wrong (cancer) will rise to above 85% by the time she’s 3 years old. If you decide to do the surgery, the chances of something going wrong are miniscule. Going under anesthesia is always a risk for animals as well as humans. But like I said, an experienced vet should get her through it just fine.
Considering she’s 2 years old already, I would suggest you do it sooner rather than later.
Thank you so much for taking poor Alfie in and giving him a good home. 