I would say the only part(s) you will need to worry about are:
They are part of the recipe for disaster quest.
There is a certain part of the "Recipe For Disaster " quest That allows you to do that, it is the "Pirate Pete" Part of the quest, do that, and it should tell you how.
(You MUST be a RuneScape Member to complete this quest)Do part of the "Creature of Fenkenstrien" quest *not sure how it's spelled but you start it in Canfis.During the quest you'll find out where they are, it's a bit difficult to explain.
You must start the quest "recepie for disaster" and do the part of the quest "saving evil dave"
u have to do the "evil dave" part of the "recipe for disaster" quest
It is a cocktail that Members can make as part of the "Recipe for Disaster" quest.
its part of the quest a voids dance
You get the Rod of Irvandis during the In Aid of the Myreque quest, it is used at the almost end part to finish the quest, and yes you do keep it when quest is complete.
If this is part of the Demon Slayer quest, then the link below should direct you to your answer.
There is no quest called "Jack Frost", it was part of a Christmas event that has now passed.
You can dye, un-decorated capes, goblin-mail ( part of a quest ).runescape is for loosers so sok my b@lls
Probably shows that you have completed it, or there may be another part coming soon for that quest.