I'm going to say a big no to almost everything in this idea. I don't see this as a good idea to begin restricting companies as much as you want to.
Nobody doesn't have to prove anything, why are you trying to limit that people want to have fun, huh?
Buying a bus and waiting for few months. In real life yes, but in simlation aka game? Nope, certainly not.
So every private company not only has to prove that it can pay and keep on working month after month, but also that incentives will be given: a company, always and from here onwards will be the private ones, if it buys a CNG bus, it will have to prove it and will receive a real life, similar to real life help. if now the EURO 6 engines are sold, every company that invests in green vehicles receives help. if a company buys a bus that is not EURO 6, every company that invests in green vehicles receives help. if a company buys a bus that is not EURO 6.
Honestly, not sure I really get what you mean here, but forcing company to be private one? Certainly not. What do you mean have to prove it? Honestly this part of your suggestion is extremely not understandable. I get it that if company buys a green bus, aka hybrid or CNG, it could receive some kind of financial support?
From time to time, BSC will be able to auction maps of both DLC and the companies that want to enter the game, the winning company will have to put at BSC's disposal whatever it requires, e. g. X10: Auction for 40,000 € and oblige the winning company to give a minimum of 10 trips per month and get 10,000 € of profit, in turn they will be forced to buy articulated, standarized buses.
Once again, you are limiting the fun people can have. I don't know about other companies, but my company is made by group of people who want to enjoy things together, what you are trying to suggest, will limit the fun we can have extremely, because we can't get the maps we want.
It will be controlled that each driver in this case players, are clean, do not go from company to company, usually play well without blows, no fuss etc... and will have a history or curriculum so that each owner of company knows who enters or who leaves.
Your suggestion actually makes people jump from company to company, because companies can't have the maps and buses when people want, so they will go to another company that have them.
Setting up a bank that is controlled by the BSC and companies may use it to borrow money.
Doesn't this basically exist already?
In the same way, this bank will have to regulate that companies don't get into debt and that if they do it and can't pay, they will close down and go out to auction.
This is already a thing, except the auction side. If company is in dept for 7 days it will closed down according to my understanding.
If they want to become private, they will have a trial period of 3 months. if it is the opposite of private to public, it will be immediate and any aid or subsidy that has a private one will be lost.
It should be up to company owners decide if they want to be private or public, no restrictions.
Finally, private companies will be ranked in a ranking that, something is being done now but it should be improved, in which if a company proves to have few blows, many travellers transported, arriving on time, things like that will be helped as a reward and also create challenges with reward for these companies.
Ranking list could indeed be improved, but why only private companies? All companies I'd say.