You are doing everything right.
As S&L says, it’s common for rabbits to get into sth called a post-spay craze after being de-sexed. It has to do with the body and brain adjusting to the sudden stop of sex-hormone production. It basically means the rabbit’s sexually driven behaviors can get worse just after a spay. Territoriality, pee-and poop marking and aggression etc are all to a great extent sexually motivated behaviors. In girl animals, there can also be an upregulation of testosterone production in the adrenal glands as some sort of compensatory mechanism. Sex hormones also have a big impact on mood. If there’s a hormonal imbalance, as in your bun’s system right now, mood suffers. In a way you can think of a spay as going into full blown menopause just overnight (unless you find that notion too gross), no gradual change, no hormone replacement therapy, just WHAM.
Anyway, a post-spay craze is all normal and the differential is pain. You and your vet have dealt with the possibility of pain. That’s great, because pain certainly doesn’t make you feel less inclined to aggression. That the aggression persists despite more pain meds, points towards a post spay craze. The smelly spray-marking supports this theory. A post spay craze resolves itself, but it can take a while. With a boy, it usually doesn’t last more than two weeks, but with a girl, it can be months. Eventually though, the body and brain adjusts.
It’s normal for a bun to have a bit of poop irregularities for about 2 weeks after invasive surgery like a spay. Anesthesia in itself slows the digestive tract, then there’s the normal post anestesia inappetence. Pain of course also affect appetite negatively. If she gets mostly critical care and not her normal diet, her gut microbiota will be a bit disrupted. This means you can get extra cecals and fecal poops with a funny shape or constitency. The bun might not need to eat all her cecals, if she is producing extra. It also seems likely that she could have difficulties reaching for them due to the surgical scar.
If you have kitchen scales, maybe you could weigh her. I’m assuming your vet weighed her before the surgery, they do that to figure out how much anesthetics to give. You could ask them for her baseline weight. As S&L also says, buns can lose weight really quickly if they’re not eating. This is of course bad and you might have to give her a bigger dose of CC daily. Some vets can also be willing to show you how to give sub q fluids at home, as an extra measure of supportive care.
You are very welcome to ask as many questions as you want to here. We’re all rooting for you and Luna =)