You can paint the inside of FP opening charcoal and then I would go for a blue/grey and not greige. Those colors tend to be very dark. You have black furnishings and a blue/grey would look very fresh. Your art above FP has blue in it, so replace rug and get some pillows for sofa that will bring in the colors of the painting. Why not just put in some shelves, one big enough to hold tv. That would give a more open concept to room. If you need one enclosed to store components, that would fit also. I would not build up too high on the wall.

I agree, I think the kitchen units are quite charming. The tiles date it, the top of the dresser and the piece over the window. Agree, would paint the ceiling a soft chalky white. I know they're becoming a little overdone but metro tiles would suit but handmade ones in a soft white unless you just remove the tiles altogether and have a splashback by the oven. Can you afford to update the floor? The dresser offers good storage space, have you considered either just removing the top half or updating the top so changing the architrave and glass panes? The fire itself looks lovely, do you need the heater in front? I also like the brick but the recesses are dating it. I definitely wouldn't paint the brick, if you were to do anything I think it would need plastering over to cover the niches unless you are able to match the brick. Do you have a better pic of the firep? If you are set on painting the kitchen units, I would look at the really dark greys and inky Blues for the base units, as I think they'd suit the style well, with brass cup handles with a very pale grey for ŵall units. Or if you want the same colour units, look at a mid tone grey.

Depends a lot on what you like really. However, if you have low ceilings as we do in an 1850 cottage, you can make the wall look taller by painting your coving the same as your walls, same with the skirting. If your ceilings are of standard height 7'6" or higher then there's no hard and fast rule, just what you may prefer. It's also quite fashionable these days to paint in that manner and also to paint the doors the same colour as the walls for a seemless look .

Could you hang the mirror on the back of your door? You may need to get stronger hinges to cope with the weight. As for paint for the drawers, either the same colour as the wall or the colour of your existing furniture and decorate as the previous commenter suggested. God luck with it. By the way . . Very neat bed-making there .