My rule of thumb:
Improvement: extends the life or significantly betters/changes the use. IE, new roof.
Repair: fixing, maintenance, replacing like with like. IE, patch roof, painting.
I would personally classify the new kitchen and floor replacement as repair, so just expense it this year. If you changed the heating system, that would be improvement (radiator to forced air).
Insurance money - I would think it would be other income for the rental, but am very willing to be corrected if that's wrong.
When you sell - if you expense it this year, then no direct impact. If you capitalize (improvement), then it would get included in the basis, plus whatever depreciation.