A little help here will be very much appreciated. I am quite confused & unsure of what needs to be done. I do see many threads on the board but was unable to find similar situation as to mine.
I am currently on Tier 1 (Entrepreneur Visa) which gets expired on March' 2017. But I want to switch to a spouse visa.
Which I understood is FLR(M) please let me know if I am looking at a wrong category

So,
1) Can I switch my visa category now considering I have lot's of time remaining on my current visa (shouldn't make a difference but who knows, rules are quite weird these days)
2) My husband is a British Citizen so how many years will I get on my visa
3) As I have plans of travel but I am interested in getting this out of my way first so is there an option to take premium service for this category.
4) My husband has got his British nationality via naturalization. He hasn't applied for his British passport at the moment & won't do for next 3 months as he needs to travel out of Country for work (he holds Dual nationality so his travel isn't a problem). So, could I apply for my application showing his Naturalization Certificate & ILR stamp (on BRP). Or his British passport will be needed regardless.
Thanks a lot, a reply would be highly appreciated.