1) it should be typed and he can just sign it. I don't think anyone hand-writes their letters
2) if the bank statements are official (mailed or printed by the bank) they do not need to be stamped. If you have printed them from online banking, they must either be stamped/signed by the bank on EVERY page OR accompanied by an official letter from the bank confirming authenticity.
3) you only need his passport photo page, nothing more. He can get it can be certified by a UK post office for about £8. Some people have been fine sending regular photocopies but if he can get certified/notarised that would be safer
4) yes... ideally you'll want to send the boarding passes as they show you actually got on the plane, but if you don't have them all then the e-tickets can be sent instead
5) yes, you MUST include divorce decrees from all previous marriages for either of you - to show you are legally free to marry again. The visa can be refused if you don't send it
Sent from my iPhone using Tapatalk