Those might be ideas for future items, but as of now we don't really have a way to determine if a Pokemon likes you (hence the use of stones to obtain Pokemon like Espeon and Umbreon).
We are planning something for these types of evolutions, though. ^^
And for an item update, I realize we need items for certain evolutions, so here's what we've got so far. Note: In order to evolve these Pokemon, you'll still need to find someone who will trade (when applicable, like to get Politoed or Steelix), then trade with in order for the evolution to occur.
King's Rock-
To Obtain: 20 posts in Azalea with your character exploring the Slowpoke Well.
Metal Coat-
To Obtain: 20 posts on Iron Mountain
Deepseatooth-
To Obtain: 20 posts in Slateport with your character exploring the museum
Deepseascale-
To Obtain: 20 posts in Slateport with your character exploring the museum
Dragon Scale-
To Obtain: 20 posts in the Dragon's Den
Upgrade-
To Obtain: 20 posts in Saffron with your character exploring Silph Co.
Dubious Disc-
To Obtain: 20 posts in Jubilife
Magmarizer-
To Obtain: 20 posts on Stark Mountain
Electrizer-
To Obtain: 20 posts in the Power Plant
Protector-
To Obtain: 20 posts on Mt. Coronet
Reaper Cloth-
To Obtain: 20 posts in Lost Tower
Razor Claw-
To Obtain: 20 posts in Snowpoint
Razor Fang-
To Obtain: 20 posts in Celestic City
If I missed any items needed for Pokemon evolution, please tell me, I may have forgotten some. XD
Thanks to Alonewithfriends for reminding me of the Reaper Cloth. ^^ 
