1.It is in the Aether Paradise.
2.Eevee might be a bug I'll check it out later. It should evolve normally for every other evolution as it does in the game.
3.They have a low chance of appearing.
4.They are usually not meant to be accessed. Just something that should be there but nothing that I added to it.
5.Some are not meant to be talked to but it is rare to find them.
6.I can remember one is given to you by Lance in the Lake of Rage if you pick his option. There is at least 2 more, one in Aether Paradise.