Bathroom jobs - which tradesmen do I need?

I want to spruce up my bathroom and need some advice about whether all the jobs listed below can be done by a single tradesman and (if not) what order they should be completed. Also would be good to know who can do the job too! 1. replace the tiles around the bathtub 2. replace the electric bathroom heater 3. treat mould on the ceiling 4. paint the bathroom