Hello Cheryl these are all good questions. I would have to say a glass top vanity would require lots of cleaning if used on a daily basis. With kids and teens expect scratching of the glass. Stone counters will last a long time but natural stone requires sealing. Sealing the natural stone will prevent staining. Today most of my clients use quartz counter tops throughout the home. The product is non-porous and cleans easily. Both stone and quartz are scratch resistant.

if you go down the stone or quartz path, ask your fabricator what they have in remnants. you'll save a bundle not buying a whole slab of something.

I would not recommend glass. Opt for honed marble (more maintenance) or a quartz product for the least maintenance over time. Good luck!