Bring some Cure Critical Wounds fruits if you can't heal. Some Free Action fruits can be useful too. And some IronSkin too, as usual.

When in island, follow the path to the North, endure the traps damage and reach top of island,

Meet Delsin and speak with him. Accept to be a spy or kill them all, good XPs. Beware of Delsin (and templars?), he can dispel you. Kill him first.

View a Bakala tree to get some wood to sell to Kalak in Caravan Way, and kill some Shambling Mound for XPs.

No more to do here as far as I know.

If you haven't spoke to Delsin you might have traps on the way back too, be careful.

Normally next time you come, there will be no more traps. It's for first time only.