Mr Punter

I have had quotes for this before and they were very expensive to cover the whole house, but can be handy for smaller areas. Get a flow rate / pressure check. You can request a very meaty supply from the water co. just for fire sprinkler purposes. Have it separate from your main supply.

Yes, mineral wool is far better than pir for this.

The res bars are good call. Easy to fit as well.

I have no experience of them but if they are a decent fabricator and you have seen their installations then why not?

Only if he gets caught naked.

Why do you think you need a demolition statement? Who is asking for it?

Well you will be by the time it is completed! Plan it carefully. Incorporate drainage along the back and through the wall. Design depends on height, what it is retaining and aesthetics.

Your builder and their contractors should provide you with RAMS (risk assessments and method statements) for all hazardous works (work at height, demolition, lifting operations, machinery operations, manual handling etc.)

If it is for asbestos, the builder can get this done. What did they quote for?

This all looks fine to me. What is your concern?

I agree. Do you think the guidance is aimed at timber and metal frame type walls?

Yes it will stop the floor dusting. One watered down coat will probably do it.

Have a read:

How very odd. This sounds like a fundamental design issue as the two flows should not meet. Get a refund and maybe try another brand, like Vent Axia.

This does not apply if the wall consists of two leaves of brick or concrete, each at least 75mm thick. See "Diagram 5.3 Cavity walls excluded from provisions for cavity barriers" ADB V1 2019.