like what type of keyframes can be imported to unity. I know visual Loc Rot and Scale dont work, but what bout the others?
You can actually import Loc/Rot/Scale IPOs from Blender to Unity - however, you have to manually export a .FBX file from Blender, then manually import that file into Unity. If you use Unity's automatic .blend file importing, it only does Bone-based animations, and not the IPOs.
For more information, read this forum thread on Importing Blender Animations.