1. Dependant on Google's money, the majority of Google comes from ads but not all of them. The deal is not directly with ads, is the default search engine on Firefox.
2. This is recently, sucks a lot but we did not see yet how they'll use that with the browser.

More importantly the biggest difference is Brave want to be like Google, is the goal of the company. Mozilla is funding the project in the shittiest way possible but is not the end goal.