you can't use whatever external monitor you have, because you need specific dpi ratio to make scaling works, otherwise blurry screen, because apple only do things for their hardware.

you can't charge keyboard/trackpad (and probably a lot of other stuff) with (some, or most) non-apple blessed chargers. i was unable to charge the trackpad fully, even in a week; had it constantly connected to charger, couldn't connect to mbp as the mbp had only usb-c ports. after few warranty replacements, someone asked me what charger i'm using, so i've tested the usb-c -> usb-a adapter and connected the trackpad/keyboard to the mbp. it charged fully, and the battery didn't died in few hours. after that i've returned/give away all apple-made accessories. fuck that hostility