If your food ends up with freezing cold and boiling hot spots after microwaving, it’s probably because of how you’re using the microwave. Don’t use the high setting on completely frozen foods. Set it to medium instead. This gives the food time to heat up evenly. Microwaves mostly heat the surface, so a medium setting works better for even cooking.
Depends on the microwave actually. I used to have a microwave with two knobs: power and time, so setting the first was as trivial as setting the latter. Now I have one with a dozen capacitive buttons and changing power settings requires a sequence of presses akin to some Street Fighter combos.
You still need to take out of the microwave and stir a few times and do it once or twice more until it’s evenly hot. To each their own but I maybe use my microwave once a week.
The entire point of running it on lower power is to avoid any uneven heating and manual intervention. Some really delicate foods I've put on low with plenty of success
Great explanation by America's Test Kitchen: https://www.youtube.com/watch?v=dJrdXRZ3PUE