The downloadable rules do not have the sub-rules for necromancy and savage, was wonder if these questions are covered.

Question one. I recall reading that for savage to trigger, the unit with savage must live, is this true?

Question Two. Necromancy. If a unit was brought into play from discard pile, and is due to go to bottom of deck at end of turn, can I scrafice that unit and make it do back into the discard pile, and if so, does it still go back to bottom of deck?

I think the card goes to the bottom of the deck regardless of if it's on the table or the discard pile at the end of the turn.

you think? How strong is that guess, or do you have a refference?

www.fantasyflightgames.com/edge_npm_sec.asp

For Necromancy the unit has to be in play at the end of the turn to go back under. Discard pile = out of play.

many players use that to their advantage and sacrifice a unit like the wight lords over and over again so they can kill a unit each time he comes into play from the discard pile. Bray Shaman is a fine example of a card that can help you do this every turn.

In answer to your first question, yes the unit has to survive