1. The total fee for a spouse is $1,040.00 including the Right of Permanent Residence Fee. Seriously, pay it upfront if you can and avoid the waste of time waiting for them to ask for it. Pay here:
https://eservicesak.cic.gc.ca/epay/welcome.do?lang=en Select Mississauga as the processing office, NOT Buffalo.
2. As long as the DMP gave your husband the Copy 2 of the medical form that he filled out as proof he completed the medical, the Appendix C can be filled out again, you don't need a copy of the one the doctor saw.
3. You can, but ensure you enclose a cover note and proof that you applied for it and are still waiting for it. In general, it is best to include all your required documentation upfront, but some persons have had luck getting away with that.
4. No, the application goes to CPC-Mississauga for sponsor approval (you) and then CPC-M will pass it to Buffalo for applicant approval. Don't send it directly to Buffalo, they will return it.
5. It is going to an address in Canada, if he gets everything together nothing says he can't send it directly to CPC-M, but if it needs further documents from you then he should send it to you so you can send it to CPC-M.