You’d probably want something closer to a USB C power meter. A killawatt would measure the overhead from the charger brick rectifying AC to DC. If you happen to have a killawatt on hand it would work fine most likely.

Not yet, but I plan on doing it. Currently running a 512GB SD card which has served me surprisingly well.

Some of the best android phones, especially for the price. They seem to last forever and have good non-bloated software + unique features like shake for flashlight (why don’t other OEMS have this?). Only complaints I have are some lack of custom ROM support and sometimes wear over time. But for the price they are almost unbeatable.