The reliable way to hire a tradesperson

Hi, I have recently had my property rewired. I am now beginning the process of redecorating throughout and have unfortunately discovered that the paint can easily be scraped off in sheets. This reveals a yellow, chaulky surface underneath with a lot of hairlines cracks. I assume this is some kind of paint on top of the plasterboard. I am just wondering what my options are please. I understand I'll need to scrape it all off because the paint needs something solid to adhere to but not really sure where else to go from there. It's going to take me an awful lot of time to work through the whole house by myself so I want to make sure I have a proper plan so I'm working as efficiently as possible. Thanks in advance for your advise all

Shower stopped producing hot water, taken cover off and there is no manual thermal reset button. What else can I do.

We have moved into a tenement flat in Scotland and it needs some renovation - we were considering making the kitchen bigger by knocking through - does this mean we need an architect or a draftsman? We aren't sure where to begin as we were then considering rewiring the whole flat and changing the heating - we are jumping around from idea to idea which means we are stuck in limbo. Any advice on how to start? Is it simply call around to builders and ask for quotes to get an idea of doing it room by room or the whole thing at once? All advice welcome.