Can I Mix n Match different Demo themes Features & How Do I create & manage groups?

Hi,

I am building a community website for meet up groups & events & I have chosen KLEO for this.. Currently I am trying to create & tis the feature in the test folder & once Its ready I will move that to Actual Site..I have few questions:

1. How can I Mix n Match Different Demo attributes together .. Like Community theme landing page, Pnterest in sub page  & other pages for other theme.. Currently while installing the DEMO content I installed the KLEO default all data.. Can i mix n match & build my site with taking the necessary attributes for diff demo?

2. Its a Meet up group site.. So registered user should be able to create groups & this should have all the group functionality like Group creation/group privacy setting/Group Main page> In group page there will be group members pics, pictures,evens … Can i do all this functionality with Buddypress groups?

3. How can I add Video Background in my landing page?