Sparton, I bumped into the log out - log in issue again.
If I log out of account (facebook) and log in with another one (e-mail), then back to original (facebook), I get the spinning wheel of death and I need to delete/reinstall the game.

Is there a way I could connect the same e-mail (on original account) used for facebook, so that I might try switching accounts only based on e-mail logins? It should already be registered on NF website I think.