Budget

 It's impossible to buy any top drivers with the starting budget, the chassis and engine are that expensive, if you buy the cheapest engine, the cheapest chassis and the cheapest driver it is still impossible to buy a top driver

Re. Budget

 It is possible to have top driver even at the begging of the season.
If you select the cheapest engine and chassis you will be enable to select one top driver and one driver with lower price.
With earning money during the season you will be able to buy more expensive elements.

Re. Budget

 It's not possible to have hamilton

Re. Budget

 At the begging of the season you are not able, but if you develop your team well and earn good money from the first races you will be.