Sorry for the delayed response. It has been a busy day at the office.
I would suggest you compile all of the documents tart you have referred to above.
Evid3nce of the subsisting relationship would be the emails, text messages, and any other evidence of communication that you can provide. You need to prove that the relationship is genuine and subsisting.
With reference to the fees, yes you would have to pay 1200 plus the NHS surcharge of 600.
The evidence you have referred to above needs to be submitted by your spouse in Havana. I would suggest that you keep a copy of everything you send.
With reference to the English language test, this also needs to be submitted. This is separate from the application. If he fails the test, he can re sit it. The test needs to be passed before the application is submitted at the embassy.
2 hope this answers your questions. If so, kindly rate the answer and provide feedback.
If you have any further questions, please do not hesitate to ask.