FLR(M) Cohabitation advice

[ImigratingLion]

Hi all, thanks for taking the time to read through this post; it may be a bit long!

I am applying for further leave to remain as an unmarried same sex partner. My partner is a British citizen. I am currently on a Tier 4 Student (general) visa, which is set to expire in the coming month as my course is over. I have some questions about meeting the cohabitation requirement, though. As I have been a student during the two year window they expect cohabitation, my partner and I have not had a particularly deep financial relationship. We do not have a joint bank account, and he is solely responsible for household expenses (mortgage, utilities, council tax, etc). I also did not have all my post directed to his flat, because I thought it would be wise to keep my university work address as my correspondence address. Whoops!

I have gone back through all my old documents, and I think that I have two sets that would be helpful. First, I have a tenancy agreement and cohabitation agreement between my partner and myself, dated May 2015. Will a cohabitation agreement be suitable as one of the six documents necessary to prove cohabitation? It is between ourselves (perhaps obviously!), but it is also signed by third-party witnesses. It also clearly lists us as living at the same address.

Secondly, my university fees records are to the correct address, with four falling in the two year period (May & Feb of the relevant years). Furthermore, I have changed things like my bank statements and mobile phone bills to the correct address in February, so I have all of those for the last three months by the time I submit my application. Between those six documents, I would roughly cover the whole two year window. My partner can submit five of his personal bank statements and mortgage statements which are evenly spaced though the gaps in my own record. Should that be sufficient?

As a further question, lodgers currently live with us in the spare bedrooms. Should they write letters of support to go along with my application? We already asked the one who lived with us the longest to write a letter, but would it be wise to ask everyone who currently lives there to write a letter confirming the living arrangements and duration?

As a final tricky issue, the university I was enrolled at was one city over! We live in London while I studied at Oxford. For three of the six academic terms, I had a term-time address in Oxford, per the university's requirement. That meant I would commute back and forth on Mondays and Thursdays, spending roughly four nights a week in Oxford for three nine weeks. How much detail should I give about this arrangement, and where should I go into the details? On the letter introducing cohabitation evidence? In a separate set of documents? I have considered showing them an example of my calendar for one of these eight week terms, which highlights which nights I spent in London and Oxford, as well as examples of communication between me and my partner while I was in Oxford (we use Whatsapp). Should that all be sufficient?

Thanks for taking the time! I know it is a tricky situation, but I am hoping to resolve it this way; otherwise, we can always arrange for a civil partnership, but that would take even long and potentially get in the way of my career!