This is only my thought, nothing official, but I'd say it sounds as if you'll be all right with what you have. There is nothing set in stone requiring leases or bank statements - those are just SOME OF the possible pieces of evidence of partnership. It's having the time covered with SOME evidence, of various kinds, that matters, and as you already know, the last 12 months is what they'll look at most closely. In case you haven't found them, here are some old threads on the subject of partnership proof.
https://www.google.co.uk/#q=site:enz...tnership+proof