I was wondering what are the risks of spinal surgery?

This should be: Discussed with the surgeon and will change depending on what type of surgery, what approach, and patient risk factors also need to be taken into consideration. As a general rule, any surgery can lead to bleeding and/or infection, and spinal surgery can possible lead to nerve damage or paralysis. Again, best to discuss with your surgeon.

Varies: It varies based upon the nature of the surgery, the severity of your condition, and also whether or not you are reasonably healthy. I would certainly discuss the specifics of your case with your surgeon.