how can anyone say the stainless steel is quality or premium quality if the gauge (ie 18/8) is not openly disclosed? we must assume it is not quality

The material IS 18-8 stainless steel which is non-magnetic (I tested it) Most probably SUS 304, probably not 316, since the cocktail materials are not saline). The exterior surface finish is brilliant polish, and fine brush grain in the interior. I think this is an excellent product and I use it almost every day.

Is the strainer fastened in well in this shaker? I am having trouble finding shakers that dont fall apart

So far the shaker is great. No problems. The wife loves it.

Is the shaker weighted?

Dear customer, it is a single wall regular light weight shaker (240g) like most in market , even the best seller. This shaker bottle is sturdy ss and can do the same job to make cocktails. Have a good day!

How do you get the top of shaker unstuck and what causes it to get stuck

Are you saying that the jigger top is stuck? Have you tried using a rubber band placed around it to get a better grip on the jigger to remove? Sounds like you might have a suction problem. Or if you have not used it and it is brand new, it might be an extremely tight fit. I have not had any problems with any parts of this shaker.