Q. Age, gender, ethnicity of executives?

 ISS RiskMetrics Directors Data provides age, gender, and ethnicity for S&P 1500 companies. (Available via WRDS. Registration is required.)

Boardex provides age, gender, nationality, and education for board members. (Available via WRDS. Registration is required.)

MSCI GMI Ratings provides age for Directorships and CEOs. (Available via WRDS. Registration is required.)

Execucomp provides age and gender for S&P 1500 companies (and some others). It is available through WRDS.  

For additional sources, see Researching Diversity in the Workplace (courtesy of Stanford University).  Note some of the sources Princeton does not have or if does access is different.