Personalization of Parallax frame

Hello, I'd like to know if I can reduce the height of the pix on the top of the home page ? Can I change any color in this theme ? Can I put social media widget up to the page, near to the menu ? Can I put the grid pix from Instagram down to the page, horizontally ? What plug-in are compatibles with this theme ? Is the dummy content included ? Is the support included ? Thanks for your fast answer !