I don't think we know re: his field of study.
With regard to the athletic coach, it was a short-term Coach position in 2002 (found in old Seminole County School Board meeting notes' PDF) that was approved by the board.
It wasn't a full-fledged state-issued certificate. He was one of the top players on Lake Mary High School's water polo team (found in an old Orlando Sentinel article from 1999) so it was likely a swimming-related, short-term coach role. It was for nearby Seminole High School.
And yes, he worked with his older brother - Jaime - at his company. Matthew James Construction & Design.
This is his older brother - aka Silver Fox (as he was known on Guru
)
View attachment 1081112
ETA: And to anyone who thinks I'm "crossing a line" w/ posting a pic of him (as people used to freak out about talking about family members
), this pic was a screenshot directly from a screenshot of his loooong-publicly viewed website for his company.