A:AnswerAs far as I know, you cannot plug an external NIC into a printer.
I suggest, check the "sleep", "Eco", or "Power" settings to prohibit sleep mode thereby eliminating your issue.
A:AnswerThis depends on what you are trying to do. If you have a USB wireless adapter that is not dual-band then the newer adapter will give you better speeds only if the router can handle dual-band transmissions. So 1st make sure your router can deliver dual-band speeds then it would make an excellent choice to change out the adapter or buy some cat6 and rewire the house for ethernet.
A:AnswerNo, it does not work if you don't have internet. This is meant to pick up a WiFi signal from your router. You need a router to give out a wifi signal first.