2) I'm guessing that it's DVI on your equipment. HDMI adds audio (sometimes) and may add some other wonderful DRM stuff, although I think modern DVI also has that. Is the connector about an inch wide female type with 3 rows of pins and either 1 or a cross of pins on one side? If so, it's DVI.

5) 80s.

6) You may want to get separates, but if you're only running the pair of 80s (as opposed to Dennis's 5 80s, 2 QS8 type deal) you probably won't need them.

I am the Doctor, and THIS... is my SPOON!