Letter from Council to state the house meets immigration standards
I've never seen this one before. All I ever provided was a mortgage statement, a council tax bill and explained that my place has 3 bedrooms.
Pictures of house and rooms (provided in the LTE settlement visa)
I doubt that these are needed.
Facebook history for relationship
Relationship photos over 2y and 9m (just a selection of spread evenly)
None of these needed for FLR. The correspondence to the two of you proves you are together and they need to be spread evenly.