WWE Main Event can have some good matches, but the normally don't add up to anything. IF you just want to see longer professional wrestling matches between people that are on RAW!/Smackdown! you'll usually see that on WWE Main Event on The WWE Network for Nine Dollars & Ninety-Nine Cents.

No. It's not necessary to watch anything. Not only is it not necessary to watch it, it's not even available to watch or TV or the WWE Network.

I've never found it necessary to watch anything produced by WWE.

you can watch one of the 4 and not miss anything important. the fact is the other 3 programs is nothing but clips or rematches from Raw so just watch one hour of Raw and ignore the rest.

No because it has nothing to do with the main storylines.