Is there a reason you felt the need to start two of the same threads?

You only going to this once, I have never regretted any upgrade on my build, only the things I dint upgrade.

Personally, I would not do such a light mortar unless you also have light brick. White or very light mortar with darker brick often becomes the focal point and it becomes difficult to appreciate the coloration and qualities of the brick. In your inspiration picture above my eye is drawn to all of the mortar lines first. I usually find it a good guide is that the mortar match or be no lighter than the lightest color in the brick, or in a brick with an extreme amount of tone variation be a little lighter than the medium range.

As far as your color scheme, what is your plan for the fascia trim, gutters, and any other trim? In an otherwise all brick home your windows and trim ideally match in color. This is largely coming from my time spent around historic homes, but I feel that windows that are not white typically do have the appearance of higher quality, because the white stands out right away as being vinyl.

Does anyone know what stone this is?

I think the white mortar is beautiful with it