Gary,

You are on the right track. A few guys have seen the light and are using Min Wax for glass work. If you just put the DAP on heavy and let it set 24 hours before sanding you will be good to go and won't need the glazing putty at that stage. In fact I learned about the DAP from guys doing glass work. It will add almost zero weight and gives an exceptional bass for the glass. The Zinsser should work perfect. You should only have a little grain raise as the DAP will do most of that already. It's likely going to take about two to three coats to fill the weave as you are expecting.

The reason I use white primer is all my work starts with a white bass coat so it reduces the amount of paint by a bit. One important issue with sanding primer on glass is don't get heavy handed as it can fuzz on you. I am hearing really good things about using Min Wax for glassing and filling. The main reason I don't (and will not again) use glass is the telegraphing of the weave to the surface. One way to mitigate it from happening is to get a lot of heat on it after glassing to help shrink the Min Wax and primer before painting.

The only thing I would do different is use .5 oz cloth. .75 is a little more than you need and the weave is harder to fill, but you will be fine, just have more patience filling the weave.