Johno he is telling the truth, mostly.

However Sundance most of the items from your vast list are superficial, such as the carpets, they are not all that difficult to change.

The only big hurdles are the promenade deck and the windows underneath. They are the only big differences,

As you said there where different in many aspects, now if they had the intent to sink it on the maiden voyage then who would notice that she had the same carpet scheme. None of the press in New York as it never made it there. You can't look at the wreck to see the patterers. Most people that survived would remember the sinking, and u can't rely on their accounts anyway. Some survivors said she broke in 2 above the water some say below it. So in that respect it can't be proven.

Where that extra first class room is you can’t look at the wreck and say if it’s a crew cabin or not,

A lot of the differences between where the rooms are in accesible due to the state of the wreck so that can't be proven.

The Olympic would be hard to insure, on that basis alone a conspiracy may come to fruition