Mem,
Welcome to our "club" but, all are sorry to have another "member". I was in your place almost 8 years ago. Papillary, high grade, non invasive tumor. Your URO was good to give you as many options as possible, although you have correctly deduced observation is not a good one with high grade.
For me, fighting made sense with BCG to give it a chance, It worked and I am 8 years out. There was a thought that my surgeons skill may have caught it all but, as he said, the danger of re-seeding was to great to not do BCG. Many do give it a second chance with interfuron should that a first induction series fail. After that he said a cystectomy was the next step. Let's hope the BCG works for you and that is the end of it.
Two last bits of info. There appear to possibly be some new agents, one called MCNA that may hit the market in the next year. It is similar to BCG as it is immunotherapy but, not as toxic in side effects. Second, there are many protocols for BCG. My URO had me do 6 weeks (once a week instillations), 6 off with another scope, then 6 more and that was it. Many suggest a maintenance schedule after the first six spread out over several years. A, few including a well respected Dr. Herr of John Hopkins does just the 6. Get that first 6 done and see where you stand!
Keep posting as you have questions. I believe you are on you way to beating this!