It’s not new. I remember when the G5 iMac came out they had numerous problems with burned out midplanes. What I recall was that the Mac when sleeping would turn off the fan and it somehow literally burned out some capacitors and it was a replacement that cost almost as much as a new Mac if it happened outside of warranty or Apple Care. I didn’t own the particular machine, but I recall a relative had one that was always running in reduced mode as he didn’t want to have it burn up. I have not myself encountered any problems so far with poor quality control of my own Apple products though.

Don’t worry about the wattage of the charger. If you are going to use wireless charging do make sure to use the real MagSafe charger as those are designed to be a lot more efficient with heat and faster than traditional wireless chargers. You can use the 80% charging when you can to increase your battery longevity.