I need space on my iPhone. However I can not sync photos to my computer. If I want to delete photos off my Camera Roll after transferring them to iCloud, will those photos be lost permanently?
Deleting photos from the Camera Roll has no effect on photos already in your PhotoStream and vice-versa.
Photo Stream is temporary so if you don't access your PhotoStream on your computer where the photos can be saved locally on your computer (there is an option to do this automatically with iPhoto on a Mac), you should import the phtoos from the Camera Roll with your computer. You can delete the photos from the Camera Roll after the photos have been imported by your computer as with any other digital camera.
If you remove them from your Camera Roll and don't delete them in your PhotoStream they will remain on iCloud.