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Place white porcelain tiles inside.....and a metre outside of the new room I would lay cream rectangle pavers and it will look amazing Get rid of all the trees and just grass and place small hedges around the fence and on one side of the new room I will put a decking the same colour as the bi fold timber trimming in oak will be awesome

If you can put doors on the whole back area and deck or pave out to a functional size for entertaining - be sure to have as close to same height as inside and the whole width of the house if possible. You could do the pergola which looks gorgeous and makes a cozy feel. On top of the pergola you may be able to do a weatherproof retractable awning if you do not want a permanent covered area. That would make a whole area for indoor outdoor entertaining in all types of weather. You can still have a step down area to grass and plants at the rear. Travetine is great and easy to hose down. You do not have to concrete them down use pavers on a good road base. You would have to speak to the experts about how to get the right height - also be sure to have a slight fall away from the house.

The east facing pergola will stop some of the east morning sun from entering your home. Therefore that back room will be dark in winter. It will not shade from the hot afternoon sun because west is on the other side. And the house would be shading the east side already. (Assuming your in Australia) In summer the east pergola will be a wonderful place to sit out of the sun. Why do you wish to angle the pergola away from the home? This will cause issue with your rain water diversion. Are you going to connect it with the current gutters, or install a new gutter system?