It will make difficult for the users to complete tasks within a limited time because from my experience I complete tasks one by one when I get time.

It’s worth setting up a few vehicles at the beginning to generate some profit, and then just checking in from time to time to keep developing the company further.

I hope in future there will be some ways to load saved files in the server to start from there saved games.

I think that’s impossible — imagine your map (with your cities, mountains, and your company) and my map, which also has its own cities, rivers, or even a different biome. How could the server possibly merge all that into one map?

It actually works the other way around — when I’m on a server that restarts every day and all the companies disappear, I can save that map on my own and continue playing solo afterward.