I decided on and told my vet the following,
Since sedation is required for x-rays, I will do the CT scan instead. Before doing so, I will need some examples of where a CT scan showed something wrong that was fully treatable/curable. Basically, there is no point in having the CT scan if it's only going to show something that is untreatable/incurable.*
At the minimum, I would also like to repeat the bloodwork and fecal. After this, I think we have done more than enough testing. Unless there are more simple tests that can be done without sedation. Meaning, I'm only going to have her sedated once, if ever. If everything comes back normal, I will just monitor her weight. If she drops below 7.5kg, (she may have already) I will have to assume it's something undetectable and untreatable, like cancer or just old age. I will then have her euthanized. I'm not going to sit here and watch her deteriorate,*she probably is in a lot of pain. Her body condition is now triangular in shape which is not good.