The reliable way to hire a tradesperson

I have a galley kitchen and really want the added space that having the cooker in front of the the window would bring. Are there any regulations to stop you putting electric induction stove next to a toughened glass aluminium framed window. (150mm away from counter top.) Shutters outside no blinds inside.

Could anyone recommend the best hot tap and filter system for kitchen tap water

I am planning to replace my bath with a low-profile shower tray, wall panels and a glass screen. The existing layout and plumbing locations will remain the same where possible. I may remove the tiles myself and I will supply all materials. My question is: for a project like this, is there usually a significant cost difference between an exposed shower valve and a concealed valve? Also, is there normally a worthwhile saving if I remove the tiles myself before the fitter starts? Thanks