I believe the feet prints mean how close a pokemon is in terms of meters. Like 1 pawprint = 1 meter.
I haven't been in a gym battle yet and i think transferring a pokemon is permanent.
IGN has a small tip video https://www.youtube.com/watch?v=QxdCXSJO3AI

Thank you for explaining it to me :3

Footprints show how far a pokemon may be away from you ^^
Once you battle a gym you select a team yellow blue or red. The teams fight to control the gyms in the area.
Once you transfer a pokemon there's no way to get it back at all sadly

Ah ok now I get it :3

Cool ^^ hope you have fun playing it~