Unzip to any writable device and run mvl.exe as you run any other .exe file. That 's it.

in Edit mode, open the first Example and run it. Change something in one of the  program commands (after reading the corresponding page of the Manual) and run it again.  Check the differences between the two runs and repeat until you master the command. Repeat for other commands and for the subsequent Examples. At some point, try to write a new program by yourself.  

.txt files are normal text files. They can be opened, changed an saved by any  text editor. In Edit mode, MVL PRO can open, change, save and run .txt files. .mvl files are encrypted text files. They cannot be edited, but can be run by MVL in Run mode or directly from Explorer. Saving programs in this format allows to exchange products among MVL users whithout revealing their code.

In the 'Save to' box, save your program with .mvl extension.

Run MVL and click RUN to open the Select File window. If your .mvl file is in the same directory of mvl.exe, double click the file. Otherwise, navigate to the directory containing the .mvl file and double click it. You can also associate the .mvl extension with a copy of mvl.exe: in this case, you can run a .mvl file directly from Explorer.

Everyone having mvl.exe  can run .mvl files in Run mode or (by associating the .mvl extension with a copy of mvl.exe) directly from Explorer.

No. .txt files have to be opened in Edit mode before they can be run. Only MVL PRO can open these files.

As many as 1000. Considering that each line may be up to 400 characters and may contain several commands, this is more than adequate for any practical purpose.

As many as your hardware can handle.  In Edit mode, run one of the Examples (for instance,  Bouncing Worms), drag the window away from the screen center and run again as many times as you like.