Is this skin cancer? (Photo)

Absolutely. Mohs have a very small recurrence rate but that does happen rarely. It is also possible that what you are experiencing is a new skin cancer in the same general location. Regardless, Mohs can be performed twice for basal cell carcinoma or squamous cell carcinoma. You should ensure...

Your forehead defect is small and would likely do well with allowing it to heal by itself (also known as healing by secondary intention).  This would result in an initially pink and then light scar that is the same shape as the defect and a bit smaller in size.  Other repair options...

You would do best to check in with your Mohs surgeon regarding post-treatment exercise restrictions.  Since your doctor knows your treatment history best, he/ she is best suited to advise you regarding weightlifting and exercising after your procedure.  Generally, for facial surgery, I...