On leakage, there was a good "Physics Girl" video where a comment in her video started an argument about whether a microwave can interfere with Wifi.
Long story short, microwaves can and do leak. The safety spec is a set amount of Ws per m2 of area, something like X watt(s) of scattered microwaves if effectively permitted, which could interfere with Wifi and other comms. However, most microwaves are much, much better than the minimum requirement, but some not by much.
Then there is the metal in the microwave. I was always one who would say, Don't put it in the microwave. YMMV but just don't bother. However, my microwave came with a metal stand and has a section on using metal, asking people to put some of the metal into the microwave with a glass of water. After 30 seconds if the metal is hot to the touch, it's not appropriate.
I even put something wrapped in foil in it and it didn't generate showers of sparks.... it did end up making "that noise" though, so I took it out. "That noise" being the light saber noise of plasma forming or the magnatron overloading the transform, I don't know what causes it.