If you did the Romeo and Juliet quest its that same house.
Yes, every few months Runescape pumps out a new quest ranging from beginner (very easy) to Special (practically impossible to complete without dying).
It's currently not possible to undo a quest in RuneScape.
Rune mechanics
The legends quest on runescape is not gone, I suggest that you check again.
You will have to find out on the day, like everyone else.
its not a certein level that you need you have to complete all the quests if you do do this and a new quest comes out you cant wear it until you do that quest
It is a quest, that introduces a new potion into the game, and is a prerequisite for other quests.
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...
It is in a way for a sort-of new player, but it does get easier, there are guides out there that show you what to expect.
The quest is called "The Chosen Commander".