Looks fine to me also Zack. I think it's just getting ready to shed that lower leaf. It will probably start growing a new one very soon. I also don't see any scale.
Well I also cleaned up the plant because it does live outside ...and it was pretty dusty...which could have looked like anything...I too think that the bottom most leaf might be getting ready to drop off...we shall see though
That white patch could be scale..spray it with some Listerine or a 50/50 mix of ammonia and 409, then wipe away any residue. I wouldn't worry about the yellow on the lower leaf.