1. Probably not, if you're having the Tracker itself fight the other creatures. You will be able to copy the activated ability and choose new targets, but if you choose the Tracker both times for the "target creature you control" part then the Tracker will die after the copy of its activated ability resolves (unless you have an effect boosting Tracker's toughness or choose a creature with 0 power for it to fight.) When the original ability resolves, it will fail to do anything because both creatures involved in a fight have to be on the battlefield for damage to be dealt.
2. No. The Forest returns as a new game object and is not recognized as the same object the Verdant Haven was attached to. The Haven will be sent to your graveyard after Ghostly Flicker finishes resolving.
1. Depends on how you intend to do this. You can activate the Tracker, which will generate two fights. You can target two different creatures you control, or the same creature twice, and two different creatures an opponent controls, or the same creature twice. If you have the Tracker fight something with 1 power, the deathtouch should kill that creature, but the Tracker will also die. If you targeted the Tracker with the second fight ability, that will do nothing when it goes to resolve since the Tracker is already dead. If you targeted another one of your creatures to fight, that creature can still fight. Note that if you targeted the Nightshade Peddler and the Tracker died, the Peddler probably does not have deathtouch any more.
2. No. Any auras on the permanents "blinked" will be removed. See the Gatherer notes for Momentary Blink.
Question 1: The tracker would gain deathtouch and it would synergise with any fighting that he did. Remember that the tracker is still a 1/1 and would most likely die after the copy of the ability has resolved, and so the original version of the ability on the stack will do nothing when it resolves because of the ruling for that says "5/1/2012: If either or both targets are illegal when Ulvenwald Tracker's ability tries to resolve, no creature will deal or be dealt damage."
Question 2: The forest will no longer have an enchantment attached to it. Whenever a card changes zones it is treated as a new object with no relation to how it last appeared, and the next time SBA's are checked Verdant Haven will go to the graveyard since it is an aura attached to nothing.