A couple of nameless island quests (Divinity: Original Sin 2)

help with passing a couple of quests)
1. barbed to freedom found the shaft,and where the second part?
2 vengeance killed Alexandra,sided with Gareth (turns to the hills, he went straight here) what to do next?the head thrown on the table of the ritual,but kV hanging...
3 bellici killed him and the entry in the journal - now we will not be able to fulfill his Commission (quest stupidly hangs,what to do?)
4 mother tree where is this tree?in the temple of Amadiyah elected not)

when passing on the path of divinity through the secret door,leaving me 2 of the satellite(they will be back or is it permanent?