Elon's roadmap is pretty much outlined in the video along with all of those questions answered, just watch that to get a good idea of how it will all pan out
The full population of early Mars colonies will be purely robotic that has the sole purpose of building the 3d printed settlements for human habitation. Martian humans will then slowly increase and be mixed with civilians and science peeps and as Space X StarShip production increases more and more people will start visiting Mars for the 2 year stretches they live there for.
We will live through these stages and what an amazing thing to witness. The first civilians will be millionaires of course as their payments will help fund Martian settlement R&D.
The really interesting part will be the first humans born on Mars, how they cope back here on Earth when they visit, and what sort of classification they have as "Martians" How cool will that be?!
Musk may be a strange kinda guy but he's building the entire backbone of the future of mankind.