Mr Punter

Keep the windows and doors open during the day when it is warm and dry outside. If you have a dehumidifier, close doors and windows and run it at night.

Opening and stirring paint, moving hoses, cleaning up, moving sprayer, demasking. They were 3 x 3 storey houses. The spraying was less than 2 days. A lot of paint. They also had a roller that was fed paint by a hose that they used for rendered walls, so no faffing with a scuttle.

Spraying is quick but the prep can take ages. Also, any touching in looks bad and tape and fill jointing really shows up under some lighting. I had some houses sprayed and they had a team of 4 with 1 guy on the nozzle.

Yes I would fix a temporary timber to the face of the brickwork and cast a sand cement infill on top of the ali cill for the back of the first paver to rest on.

I am not sure of your setup but a raised tray can help if the fall is tight. They can look fine and can allow better access. Noggins or joist trimming may also be an option.

And I think there may be a small issue with the dust extraction...

If it is the case that you could buy the plot without needing to sell your place it would be a more compelling proposition. Is your offer subject to anything else (planning, easements, etc.)?

I thought you were going wall hung, hence the frame?

What is on top of the XPS? Is the garage heated / "conditioned"?

If they are not carrying current I don't see what this would have to do with BC. If they are compromising a fire rated ceiling or floor you would need to fire stop them.

I don't think you are missing anything. The way buildings behave can be very complicated. Building geometry, local climate, weather, occupancy lifestyle, heating, ventilation and insulation will all impact roof condensation.

+1 I have used these and they work well. You do need a perimeter edge to retain the paving but that is the case whatever you do.

A while ago my next door neighbour locked themselves out of the house. After a while it was decided to break a window at the back to gain entry. I was voted for the job. It took over 5 minutes with a hammer to get through the triple glazing.

Fermacell is Gypsum based, like plasterboard. It is not as brittle as cement board. No special requirements for tiling as far as I know. You have done well if you have managed to line the whole place with Fermacell as it is heavy and difficult to cut and fix.

You should keep your patio level 150mm below DPC to avoid damp issues. Patio level with internal floor level is asking for trouble.