Installing MI Crank Pulley?

[oliveskate]

Well I'm going to install my MI Crank pulley again.
Last time I had a glazed belt and that just caused issues so i removed it and re-installed the factory one because I thought it was the pulley it self. But I'm thinking I had the belt too loose/or too tight.
Just have some questions.

I got a fairly new serpentine belt (oem with around 5000kms on it)
so that should be good with the pulley im guessing?
Also when I have the new pulley installed, I should probably be able to only twist the belt 90 degrees? Or is their another way I can tell the proper tension on it?
Also after I have the car idling for 10 minutes or so with the new pulley on, should I re-adjust the belt?

Thanks you.