I cannot personally go to Spider Island for reasons I won't get into right now, right here.
But the White Spire and all we have are at your disposal, Durl.
Anyone who plans on going needs to have some Release and Purify potions on hand. I have Purifies aplenty, but for Releases, we'll need to implore upon those who can create them or find a merchant.
Beyond that, I agree -- a smaller group is perhaps better and everyone needs to agree to stick together, to run in, grab what is needed, and then get back out quickly. Perhaps no more than five, three who know the sword and two who can cast/heal. I would also suggest taking the Waystone. A boat, even with Marcena and her crew to help, seems uncessarily dangerous, not to mention time-consuming when we are already pressed for time. I also agree that going during the daytime, when one can see is the best idea.
Again, any resources I or the White Spire have are at your disposal. You need only ask.
Good luck!