Judging colours from photos is fraught with danger as they appear different on different devices. And choosing whites is not easy. However I’ve just gone through white selections in my renovation and have warm greys in the house. I narrowed down to Casper White Quarter or Lexicon Quarter. Both will work with warm grey. Sounds like Casper for you as you already like it!

Yeah I know what you mean... I have to paint it anyway as it needs repainting and the colour that is there has a pink undertone which really bothers me. not a pink person at all... So you would suggest just staying with an antique white or something and just adding all my colour with accessories?

Getting professional help would be wise , I think painting all your trims in the garage colour and the porch cover would look beautiful, you can see from this inspiration photo how beautiful the stone looks with the lighter colour, just a few ideas for colour combinations that go with your stone.

The black around your fireplace looks good, I would leave it. The green colour isnt so bad it is just kind of flat and you have no large art pieces on the walls. You could paint or just rearrange what you do have until you renovate. Kmart has the poster frames which are a good size, just rematt existing art or paint your own art to fit that size frame and hang so you get a huge chunk of the white you want without sacrificing the colour he wants or vice versa, get a large piece of mdf and use fabric and make it into art/colour and paint the walls white. You could also do panelling down the bottom in white and keep colour up the top. I am also not a fan of white walls :)