You can find something about this in the Adobe Developer FAQ. (It's a PDF document rather than a web page, which I guess is unsurprising in this particular case.)
The FAQ notes that the use of the command line switches is unsupported.
To open a file it's:
AcroRd32.exe <filename>
The following switches are available:
/n - Launch a new instance of Reader even if one is already open
/s - Don't show the splash screen
/o - Don't show the open file dialog
/h - Open as a minimized window
/p <filename> - Open and go straight to the print dialog
/t <filename> <printername> <drivername> <portname> - Print the file the specified printer.
It's for version 7 but all the arguments I tried worked.
As for closing the file, I think you will need to use the SDK, or if you are opening the file from code you could close the file from code once you have finished with it.