pipe run for new stove

[daWilko]

Electrician here will test circuits at plugs and cu and sign them off ...

Hi - BS7671 Electrical Installation Certificate requires the installation method and workmanship be confirmed. An Electrician would do this by doing the installation themselves or by staged inspections of a supervised person's work. Testing at the plug and CU is important but not sufficient, I'm afraid. Perhaps you are describing a Condition Report?

 

[Best]

Have the 28mm pipes bent by a plumber using a bending machine.
Where you have to do a horizontal run, it just needs a slight rise, especially on a short length.
Critical that the pipe is supported so to keep it at a continual rise.

 

[quality]

A bit of knowledge and ability will enable you to install what you want but on your head be it. Your suggesting a system that most plumbers have never even seen let alone designed one that works efficiently and as desired