Nikon(G)-EOS fit for Nikon G Lens and Canon EOS Mount Camera ,your cannon 80D is E mount camera, so the adapter ring is fit for your camera 

The adapter for a EOS body to a Canon FD manual is the adapter needed. The Canon AE1 uses the FD/FL lens mount. The one I purchased works without a hitch. Mine is a K&F Concept Pro lens mount for Canon FD, FL lenses. From a F1 to a 5D Mark 4 with no issue. 

Yes 

FD-EOS fit for Canon FD mount lens and canon EF mount camera body. canon 60d is EF mount, so the adapter ring can work with your camera, but you need to check your lens mount. could you pls let us know your lens specific model? service(AT)kentfaith(DO NOT)com, Please note: It is not same between Canon FD mount and EF mount, this adapter ring is only for Canon FD mount lens, please contact us if you want to purchase for Canon EF mount lens. 

If you are referring to the Panasonic DMC-G7, then yes, it will adapt any Canon FD mount lens to any micro 4/3 mount camera. Including yours.