Are there homeopathic and/or physical therapy treatments for spinal stenosis?

Surely... There are a number of remedies for spinal stenosis; but none are miracle cures! check with your primary care physician before starting any new treatments/supplements; you may also need a good orthopedist and some imaging studies(xray, mri, etc) to obtain a baseline for the degree of your 'stenosis'. Physical therapy can help as well. Best of luck!
Yes . There are exercises you can learn. Through pt for spinal stenosis as well as trying a zero degree lordosis back support. Exercises like biking, rowing and walking up an incline will flex your spine creating more of an opening of the spinal canal.