Below are some more "neutral" grey colors. I think Passive would be enough of a contrast against your roof. I am not sure if it is too blue for you, but if you go much darker there won't be enough contrast with your roof (as previously stated) . Yes, with a medium grey or even a light grey the BM blythe blue is too light and almost looks grey. Choose a color that stands out. Like the other suggestions, you can leave it, because it would look great, or choose a bold color. A teal would also stand out nicely.

No, not over the brick. Your windows and doors etc would need adjusting, along with other things. You could, of course, remove all the brick and do the wood siding like you have on rest of house. I would just do a paint wash. Anything else could be very costly. As long as you get the brick to blend in (try to use the same color gray as you have on rest of house in a paint meant for brick ), it will all look great. A nice color on the front door, to make it show up as your entry way would look nice too. I also agree, the garage doors and the garage entry door, should be the same color as the body of the house. For your main front door entrance, I see a bright darker teal. Something that will show up as your main entry.

Pratt & Lambert have a few interesting yellows ... cassava & buttery. I’d steer clear of anything too intense & “taxi cab” looking.

I would go for a bright color preferably in a cool color. Each of the samples above are all too muted in color which doesn't offset it from the brick. Try using a bright cool white.