I can't seem to find a comprehensive list of commands, flags, and things I can do from the command line.
WiX installers will take the standard Windows Installer commandline switches, as documented in Command-Line Options.
Any additional parameters that are added to the commandline will be passed on to your installer if you're using a custom Burn installer.
This was confirmed by the primary WiX maintainer on the WiX mailing list: http://windows-installer-xml-wix-toolset.687559.n2.nabble.com/Running-Burn-driven-installer-in-quiet-mode-command-line-parameters-tp5913001p5913628.html
Yes, absolutely. Burn supports parsing the "standard package switches" and will pass extra switches on the Bootstrapper Application so it can apply additional behavior.
The complete list is dependent on the Bootstrapper Application you pick. The wixstdba supports only the "standard package switches":
-q, -quiet, -s, -silent = silent install
-passive = progress bar only install
-norestart = suppress any restarts
-forcerestart = restart no matter what (I don't know why this is still around)
-promptrestart = prompt if a restart is required (default)
-layout = create a local image of the bootstrapper (i.e. download files so they can be burned to DVD)
-l, -log = log to a specific file (default is controled by bundle developer)
-uninstall = uninstall
-repair = repair (or install if not installed)
-package,-update = install (default if no -uninstall or -repair)
- Yes, as noted above extra command-line parameters are passed to the > BootstrapperApplication and it can set Variables to flow into Chained Packages (ExePackage XxxCommand attributes or MsiPackage/MsiProperty element).
You may want to also be familiar with the standard installer command line parameters: Microsoft Standard Installer Command-Line Options