@Vanillacello hola. You can pass the CR-Nicaraguan boarder via Los Chiles. I did it and the entire process lasted 20min.
@Vanillacello you can cross into Panama by San Vito without legally crossing . I don't know how but I know that people do, to buy gas. Once you get down that way just ask somebody how to buy gas.
Costa Rica and Nicaragua have a border dispute over their dividing river. This isn't Europe's Schengen area.
PS I always Favored Nicaragua for my crossings before Getting Perm Residence ...