I really can't answer all the questions you ask, as I''ve never done it, but I'll give you a couple links related to this.

anyone know how to extend time in dreams (me asking this question a while back)

The Monk who lived 100 years in a night (discussion about just that, mostly people arguing about the possibility of time extention, some actual claims of success)

As you'll see if you bother reading those, many people don't believe this is possible, but some people claim to do it, so I believe it is possible, just very hard, and must be done correctly (I don't know what correct is though), but as for the particulars, I can't tell you anything.