Sigvatr is right, as usual.
I personally think that you would do fine to start games at 1000 points.
With my beginner-friends I would start at that too and games could last for hours because things go very slowly at the start.
a) Like I said too, read everything a couple of times and 'goldfish' (It's when you play against an imaginary opponent)
Just take some dice, put down two units and let them shoot at each other and try to figure out what needs to happen.
Someone on this forum made an awesome reference-sheet:
https://dl.dropboxusercontent.com/u/4104995/7edRef_V2.pdf It's useful if you want to find something very quickly, but it's almost useless if you haven't read the
BRB or don't have it with you.
b) Agree.
c)
http://i129.photobucket.com/albums/p235/farseeryestare/40KTournament2007037.jpg Click that link, I dare you! They look terrible and you will probably feel bad because you spent a lot of money and they end up this terrible.
It's as if someone told you a joke. Every day. For the next two years. And then charged you hundreds of dollars for it!
http://darkfuturegaming.blogspot.nl/2012/05/necron-royal-court-with-nemesor.html That website has the only acceptable pink-Necrons in my opinion and even they look quite silly.