1. Yes-however, use the higher gauge wire for the longer runs.
2. No and Yes -- sounds like crap, but it works. I heard a massive improvement in my total piece of crap speakers (I mean total piece of crap-shelf system speakers with Radio Shack drivers crap) when I went from tied together and electrical taped 18 gauge to 16 gauge. Same type of wire-Radio Shack.

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