Como borrrar el progreso - resetting account

Puedes volver a enviar nuevas respuestas y sobreescribir las que ya tienes. Creo que para iniciar de cero la única es crear otra cuenta o decirle al admin que te borre tus respuestas.

If you want to submit solutions in different language - they will be saved along with old, not overwrite, so it is ok.

Creating other account is also ok, especially if you put links in profiles, to each other.

As to ask admin to delete solutions - normally programmers don't like to delete anything, so admin, as programmer, also prefers not to do this unless very necessary :)