Is there any problem with having my tongue recently pierced, and having foot surgery soon?

Notify anasthesia. This is unlikely to pose a risk (i.e. Infection) to your foot. Many anesthesiologists want tongue piercings removed prior to surgery, however.
Piercing. I see no contraindication, but anesthesia will require it to be removed before surgery.
No . As long as there is no infection there should be no problem. Be aware that the anesthesia dept. Will probably have you remove it for safety.