Yes, sir.                    

Yes you need some kind of an aerial or cable to connect to the TV tuner in order to pick up anything.

a TV tuner only receives whatever signal you plug into it. you could theoretically plug an RF switch to it for retro gaming. but without anything plugged in, you will not receive any TV channels...

it's just like an actual TV.

i think so, yes. how else will the tv signals be collected?