I think it's a matter of taste. I believe glass tops are fine. 1/4" should be plenty, 1/2" will look funny, IMO. You do want to have an air space underneath. Otherwise, liquids will wick in via capillary action and you can destroy your table before you realize it. Avoid the clear plastic "bumpons" as spacers. These can eat through a finish via a phenomenon known as "plasticizer migration." I always recommend stick-on felt pads to people. About 30 years ago, I had a cabinet shop make a slip-on cover for my wood table. We used it for every-day use when we had 3 young children. It is similar to an island countertop, but slips right over the table and slips off for formal use or to add leaves. One of my daughters is having one made for her everyday table as we speak. Ours and hers will be covered with HPDL ("Formica") in the color and style of choice. Just for reference, her cabinet shop is quoting her just under $400 for her topper.

Congrats on the new little one on the way - how exciting! So, I come from the camp of "be careful, but not too cautious". Children get bumps and bruises, scratches and boo-boos...it's part of them growing up. You want to put them in a bubble and keep anything bad from every happening to them. Alas, I'm not sure that makes them well equipped to handle the world then. So, be careful...but not too much...what a tough balancing act. But, I digress. Also, something that I'm always reminded of is people wanting to save something "for good". My grandmother did that - they were of very modest means, so when she got something new, she always put it aside to save it for "something special". Well, there are plates that are in the china cupboard to this day that were never used because they might get scratched or chipped, so they should only be used for extra special company. Who is any more special than your very own day-to-day family, really? So, enjoy that gorgeous table. Embrace the dings, scratches, and dents that will come along with having use...remember what those come from...those are the things of memories...they are the things that you will reminisce about when your little one(s) are grown and gone. You will learn to see that dent and remember the day that your little boy (or girl) decided to ride his tricycle in the house and banged into the table leg and dented it, cried because he fell off and bumped his head...and stopped crying because you kissed away the hurt (that DOES work, you know!) And you will grow to love those dents (or at least the stories that go with them) more and more and more as the years fly by.

Are you having the glass top cut to order? If so I would think that would be the person to get the best information.

Let me guess -- dark colored table, with a fairly glossy finish? Modern finishes are tough, but they're no match for ceramic plates, glasses and silverware. Light scuffs that can be seen in glancing light are difficult to avoid. Is there anything I can do to protect it in the future...? Coasters, placemats, tablecloths. Or, you can let go of it's perfect newness and let a patina develop. Wax can hide those light scuffs, but then you'll have to be more careful with glasses of icewater and such, which will leave (repairable) white rings.