I don't have a picture handy, but the Aeolus rims are 27mm at widest point, which is above the brake track, they are about 25-26mm at the edge where the tire sits
I can see just a bit of rim on either side of the 23 tire. That's what you want for best aero, rim 105%+ of tire width
Never had an issue with extra rim width, 23 and 25 tires fit fine, same story on my prior even wider wheels 303 firecrest and EC90 55
The Zipp SL Speed is advertised for dry conditions. I wouldn't use it in the winter... I've had a slide out on wet leaves after a rain, even though the road was dry
Everything about building wheels, glueing tubs, etc.