Is this matteress delivered rolled? If not, can it be bent slightly? I ask because I'm concerned that it may not be possible to fit a super king up my stairs.
No, this mattress is not delivered rolled.
The mattress can be bent slightly but this can cause damage.
If you are concerned the mattress may not fit up your stairs, you can select a Zip/Link mattress which is a Super King split in half and then Zipped together.