1. You can speed up flights just as you can in FSX.
2. You can save a flight just as you can in FSX, but not every piece of data is saved just like in FSX.
3. Because FSX is old computer code and MSFS 2020 has been re-coded from the ground up.
You can save plans as much as you want, but you need to understand what is saved when you save a flight plan. No, saving a flight plan does not mean you can resume that flight where you left off.
What is your general programming background?
What is your gaming programming background?
How much money have you set aside for the project?
Do you have other funding streams for this?
1. No, it is not.
2. You access the systems and FMS in the cockpit of the aircraft you are flying, either on the control panels or from the FMS located in the cockpit.
With your normal connection, start the update, go do something else, check back in a few hours. Nothing you do is going to speed up the MS servers or eliminate the hundreds of users also trying to update today.
Internet speeds also depend on the computer/server at the other end of your connection. In this case it's Microsoft servers trying to allow everyone to access the same update.
Its because thousands of US users are all updating at once. Yep, just leave it alone and do something else. And now East Coast and Central time business are all closing for the day.