Hi Sounds like you are at a point where surgery may be needed to help improve the quality of your life. 5 level laminectomy does sound excessive and there is a risk for instability.
Questions I would ask the surgeon would be
1. Risk of developing of instability with 5 level laminectomy
2. % of success with the surgery and expected symptom alleviation
3. What would happen if he limited the laminectomy to specific levels that are affected the most severely or perhaps identifying which levels are causing the neural symptoms
4. It would be great to do some research on your own and also read more on the operation, success rate yourself. Pay attention to the number of the multilevel laminectormies in these articles as well. For example, this one here, I believe the most was 3 level https://www.surgeryresearchjournal.com/open-access/spinal-instability-following-multilevel-decompressive-laminectomy-without-fusion-for-degenerative-7295.pdf
Use citations of this article to find other articles to do more research. Then you can ask better questions and go into your consultations informed.