The Insurance position?

[BIG MAC]

Is there a definitive text that anyone can point me at in relation specifically to insurance of a domestic property which covers the following areas?

1. Electrical works (significant but not a full rewire) if carried out in accordance with standardes and normes does this subsequently need to be certificated by a French trades person?
2. Plumbing works I have a mountain of UK standard copper pipe and fittings which I would like to use I have read my policy and see no exclusion in respect of using fittings from another EEC country...ie. taps from Italy, sinks from Germany, shower cabinet from Spain...why therefore would UK fittings be excluded from being covered?
3. Solid fuel stoves - I have an old Quebb Master stove sitting in my hangar but as these were made in a foundry in the Forest of Dean and this no longer exists can I legally install it?
4. Hinges ironmongery etc - These items when bought in France fall into two categories - French made, decent but prohibitively expensive or Chinese made affordable tat...surely these can be 'brought in' without penalty?

Bottom line - despite all the scare stories is there much narrative in respect of French Insurers swerving a claim in respect of any of the above (I can imagine electrical would be the likely one)

Big question - In relation to third parties...if a visitor to a Frech home in some way suffers loss or damage as a consequence of DIY lets say they slip on a tiled floor which is wet due to a weep from a UK spec rad valve onto tiles bought in the UK...What view would insurers take (All purely hypothetical of course)