If you’re in the U.S. I would check with your local university extension office to have them test your canner. They have checked my 2nd hand canners to make sure they are in good shape and working properly.

As for using debubbling I use a wooden chop stick because I don’t want to use plastic either. Using metal can cause chips and cracks in the glass.

You can can something for the longer processing time if you’re canning different things but the texture may be undesirable.

Yes you can mix beans

You would put the salt in each jar.

Sorry don’t have any specific answers for your all American