Try diggers paint brush restorer. Small patch first, you don't want it to spread it. Failing that there is a company called So Safe. It produces graffiti remover and will get rid of that in minutes. My guys use a lot of it with very good results.

If I walked into a bathroom that had painted tiles and I didn't have the money to repair it, or I liked the original yellow, I'd be dark. Once you paint it, the tiles will definitely need replacing at some stage. At work I always say, will your quick fix make more work in the long run. Change the taps to chrome(stainless is too expensive) and leave it. It's a clean functioning space that will not turn anyone off.

write to him and say you're not satisfied with the work and can't pay for such a poor job after you already gave him a chance to fix the problem but it's still not good enough... send photos of each problem area and ask what he suggest could be done to fix them (keep duplicates of all emails or letters).....he may ask for another chance to fix the problem or may decide not to ask for the rest of the money...the only consolation is that you will have a poor job for half the agreed amount and/or you may decide to give him another chance. Unfortunately crooked tiles can be a problem in lots of houses where walls are never straight but a good tiler expects and will compensate for this.. removing tiles can break them and damage the surrounding tiles so i hope you've kept some spares and if necessary explain the problem to your tile supplier to recommend another tiler to try and fix the problem ...hopefully the rest of your reno will go well, best of luck to you

leftover Modwood from our balcony was used as decking for a jetty on our farm dam and despite being camped on by ducks and kangaroos the surface of the balcony and the jetty were both ok with bare feet and although the ducks did leave some staining and the surface did get hot it wasn't slippery when wet and i understand that newer Modwood colours are better and i can't believe that a toddler's bike or dogs would cause any more harm than the average adult shoe and having never used any other decking product i can't compare