Un-tick the sorting option at the top of the list.
Click on the related links, for a list of special quest rewards.
You find all the quests in the quest list, click on the quest tab.
See related links, for a list, at Runescape Wikia.
It's currently not possible to undo a quest in RuneScape.
During the quest: Creature of Frenkenstrain, you find an underground cavern that is full of them... I highly recommend the quest for anyone who wants to do experiments!
You get darklight during the quest "Shadow of the Storm". You can find the steps of this quest, and others, in great detail on sites such as runescape.wikia.com.
The legends quest on runescape is not gone, I suggest that you check again.
A quest on Runescape is an adventure that puts you in a conflict, you solve it and you get rewards like money, skill experience points, quest points, and items.
If you quit runescape...
The quest is called "The Chosen Commander".
The quest Swept Away was released in RuneScape at the same time as the Halloween event in 2008.
There are many websites where one can get advice on completing a Runescape quest. The Runescape website itself offers advice as does the website Tip.It.