So many questions; so little time.
Visas are the easiest part of your planning. Find out the location of the nearest consulate, or embassy of the target country, phone them for information what you (identify yourself with your citizenship), must do to apply, and ask them to send application forms, or find out if you can download them. The problem is the bike. Russia and Mongolia no problem. But China is. Some have managed to sneek in without the official paperwork. But don't count on it to duplicate this. The official way is still to arrange for an escort in advance, who will do all the required paperwork for you for a tidy sum of money. Check the HUBB for the latest info on this. You arrange for the Chinese visa (easy); they will do the rest.