I agree with kittenfish. It's not like you're applying for a fiancee visa where you need to prove the relationship is real and you've met each other - you're married. Honestly, I'd send maybe 5 photos pre-wedding (spaced out if possible), the marriage certificate, and a wedding photo or two. That's it. Between the fact that you're actually married (and have proof) and your letters of intent, I don't see a reason why you'd need to include any of that other stuff.
Also, I'm not sure you need letters addressed to each of you. That kind of documentation is needed for ILR applications, not for the initial FLR. Unless you're trying to go straight for ILR, in which case, I have no clue what you need for that.