You can finish this quest more than one way. You can dispose of Roland and get your reward from Seridur (just murder Roland in his cabin). Or you can talk to Roland and decide to murder Seridur instead, in which case you go to his cave hideout and kill him and his vampire chums. How difficult this is depends on what your character is like and where you have set the difficulty setting.
You can't cancel a quest, you just dont do it.
i dont think so
Kill a monster and get it from it
There are no dragons in unmodded Oblivion, except for something right at the end of the main quest.
look for a oblivion gate and kill deadra that is how you get the hearts you can clone them
No
The quest A Brush with Death In Cheydinhal.
Defeating Mehrunes Dagon will close the Oblivion Gates, but you could still visit Oblivion afterwards if you do Peryite's daedric quest.
You need to be at least character level 20, before Boethiah will give you his quest.
You have to complete the quest for the daedric prince Nocturnal. You can get this quest by making an offering to the Shrine of Nocturnal and at the required level.
the orrery is a plug-in which means it has to be downloaded
Go to the link below, and go to the oblivion strategy guide. Then go to the quest with the statues it will tell you where they are.