I know you've seen a thousand of these but hoping you will be kind enough to answer my questions anyway

I am gathering the documents for the Accommodation Requirement and I have the following:
In Joint Names -
Water Utility Bill - November 2017 (Addressed to Sponsor but has Applicant listed under "Additional Account Holders" on the first page)
Council Tax Bill - March 2018
Council Tax Bill - March 2019
Council Tax Bill - September 2019
Individual Documents - Sponsor
Bank Statement - January 2018
Bank Statement - June 2018
University Fee Invoice - September 2018
Bank Statement - December 2018
Employment Letter - June 2019 (perhaps muddled by the fact we're not actually including his salary as he won't be in the job 6 months and I meet the salary threshold with my income alone)
Individual Documents - Applicant
Bank Statement - January 2018
Bank Statement - June 2018
Letter from Thameslink regarding delay compensation for season ticket holder - September 2018
Bank Annual Summary - December 2018
Pension Enrolment Letter - June 2019
Leases
Address 1 (4/11/17 - 3/11/18)
Address 1 (4/11/18 - 3/11/19) - we broke the lease early
Address 2 (15/03/19 - 14/09/19)
Address 2 (15/09/19 - 14/03/20) - where we are currently living
So my questions are:
1. Is submitting a document that was generated and recieved online (no hard copy) acceptable?
2. Are all those sources "official" enough?
3. I am planning on applying around the 15th October - as you can see our leases started on the 4th November 2017, prior to that we lived with his family. So based on these documents there is a 3 week gap at the very start. I am wondering, do I need to get a letter from them saying we lived there, or is that a small enough timeframe that I can ignore it? Perhaps helpfully, our first lease does list both of us at our prior address on the document, will that cover it?
4. Because both our names are on the lease, do we need any additional letter from our landlord stating size of property or anything?
Thanks very much for your help!