I like the look of the grout in the pulled back photos.

It's within acceptable parameters for a professional job. The misalignment is visible, but not prominent. Live with it for a few days. Before you tear it all out, ask the installer how much it would cost for him to re-grout with white grout (a messy and tedious job...). That will make the corners and misalignments much less visible. Whatever you decide to do, make sure to seal your grout.

Back up to the normal viewing distance and take a normal picture.

Unless your visitors are going to lean forward, stick their heads under the cabinet and pull out their lorgnettes ... that looks fine.

I like the way the grey picks up the grey specks in the counter.

I think white grout would have made your backsplash stick out like a sore thumb with those countertops. You need the grey to pick up the color in the counter. Wait until it's all done and you'll see he was right. (Well personally, I'd have preferred a narrower grout line, but it does look fine.)

I like the grey grout with your counters. The wavy corner isn't ideal. Is that something he can easily fix?

Grey grout looks good.

The misalignment looks to be up under the upper cabinet so I don't think it will be particularly noticeable. However, the pattern would drive me nuts in that it doesn't flow--the first and second picture show awkward corners, but perhaps there is a reason he hid those there that I can't see from the pictures. Depending on how much the installer charged I would be tempted to make them redo it to fix the pattern. I don't mind the gray grout, but it is less forgiving than white grout.

I think white grout w white tile would have been too stark w your cabs and counters. I see your concerns and would probably be obsessing over them too if I were you (cause I'm a nut) but I've learned nobody but me ever notices stuff like this in my house. Any time I point out some flaw that I think is glaring people I trust to be honest swear they never noticed it. You can relax - you'll move past it and not notice it once you settle in.

I was unhappy with the corner of my subway tile. This was my solution.

That looks great.

Looks fine.

I think it looks great. We had an issue in our bathroom BC the floors weren't level in our old house...So in order to make the top perfect, the bottom was a little uneven. Trim was our solution, now it's perfect.