On the sponsorship issue, I assume it would be more profitable for a company to invest in an unknown driver just breaking through into F1 instead of paying over the odds to sponsor an already established driver.
It probably would be.They would attract more media coverage that way.But the risk is that the driver may not make it to F1.
Drivers such as Perez and Maldondo picked up their sponsorship early in their careers in the lower formulae with no guarantee that they would ever make it to F1.