Yes. They do not work at the same site nor by the same mechanism.
Absolutely!
Yes, although doing so makes no practical sense.
I kinda wonder that myself...I am running my 12v LED computer fan from a 12v battery pack from my Ryobi drill with the charging cable inserted into the battery...it says its charging, and my fan is...
I burned my hand because I tried to remove the pot from the burner while answering the phone at the same time.