Congratulations on getting your new build underway. I'm not an expert, but am doing my second kitchen and have gleaned a lot of good info here over 7 yrs. I'm happy to offer my opinion on some things you're questioning.

I would do a hood vent instead of a microwave. It's so much easier to do it while you're building instead of trying to retrofit. If you've been on GW for a while you've likely read many of the practical reasons for good ventilation. I know some spaces are so small (apartment/condo kitchens, etc) that micro hoods are the best choice, but I think having it as a focal point in the kitchen is not desirable. If you don't want to give up cab space, there are some small but efficient countertop models you could set right on the counter beside the fridge.

I also worried about going to the ceiling w/ cabinets but my vote is to do it. I don't think you'll find it overwhelms the space.

I would not go with all glass uppers unless you want to showcase everything in your upper cabinets. I think a touch of glass with nicely displayed dish ware or decorative items gives the feeling of lightness more than a wall full of what most of us typically keep on hand for practical purposes in our top cabs.

Lastly, I am a big fan of SW Dover White. It has covered almost all the walls in my open plan home and I've liked it in every season and every light.