No. Split-screen will detract from the game
Yes. Split-screen will be beneficial
Does not matter.
I think 4 player might detract from the playability unless you have a massive television. I think 2 player would be more likely to happen in my opinion.
I always found split screen lagged out b orderlands. Where destiny is on servers might be ok but why would you wanna cut your tv in half? Or into quarters?
As much as I would like that, Skyrim doesn't allow split screen either.