The domain is 'free' for the life of the hosting. That is, you will not have to pay a registration renewal fee as long as you maintain the hosting plan.
I don't believe so. Of-course, the new registrar will probably request that you pay for another years registration when you transfer the domain, but I don't believe DreamHost will charge you anything to transfer the domain.
Save [color=#CC0000][b]$50[/b][/color] on DreamHost hosting using promo code [color=#CC0000][b]SAVEMONEY[/b][/color] ( Click for promo code details )