did you inform the contractor of the mess? I've never heard of a contractor rinsing the buckets inside - they usually go outside with a hose. He may owe you a new tub!

FYI My contractor did the same thing (in an apt). Tub looks awful now and was brand new...

I was going to post this question also. Only I have it around the toilet bowl on a tile floor that the plumber left. I too scraped the large stuff off but can't get the rest and now it is discoloring. Any help?

Contractor might also owe you new plumbing lines :o Depends on how much grout he washed down the drain. That's a BIG no-no :(
Try Gel Gloss (I get it at Lowes) to bring back the shine and reduce the appearances of scratches on the acrylic tub. It's in a pink spray can. On the tile floor, you can try a grout haze remover. That too can be found at home improvement stores.
Monica