Is It Safe To..

My discs clonk when I grab the front lever, that's what these type of discs tend to do.
If you can post a video of the play that may help?

 

Caution! Never put oil of cloves(or any other oil ) near your brakes!

 

Looks like the carrier is worn/corroded to me. New disks, please!

 

I sold my GTR a few weeks ago with 31k on the clock and had used two sets of pads front and rear, but I am a fanatic cleaner of my bikes and always rotate my bobbins weekly uninformed brake cleaner, and removing the pads for a clean as well, took all of 30 mins and gave me piece of mind.

As for swopping left to right you takes your own chance, personally I would purchase new.

 

yeah, I've used those Min.Th ones before, pretty common make and they last well.

 

if they are not marked L or R cant see why swapping em round would be an issue.