The one piece of data that is not in my sheet and might be useful is the depreciation rate. AFAIK this is only available on the aircraft info page so must be compiled manually.
Indeed, I have the same issue. My spreadsheet has everything except the depreciation rate; to find it for each aircraft would require buying one of each. Perhaps I'll do it in a sandbox world one day, just for fun. The data really isn't particularly useful in most cases, as you mentioned, except those who want to play Lawful Good and min/max everything without resorting to scam IFS, etc. I outlined one such method here, which does indeed require knowing the depreciation rate.