The start with Windows is a VoxCommando bug, not specific to MP and I have what I think is a working fix. It will be in the next release, as soon as I tie up a few loose ends.
Unfortunately the ActivateWindow bug affects many of the commands that we are using, but it works as well as it works. If these commands are not causing you problems then great. I just meant that i"m not going to waste any more of my time trying to fix MpWifi or Mediaportal itself because I obviously don't know enough to do it myself, nor do I have the time to spare.
As far as I know there is no way made available by MpWifi yet to browse an artist, or jump to a particuarl album etc. You can only add them to the now playing list. Of course you can then jump to the current playlist and see all the songs by that artist/album etc. The reason you can jump to a particular movie or a particular season of a tvseries is that those plugins have provided load parameters that allow us to do that. Unfortunately these loadparameters require us to use activateWindow so on my system anyway that means glitches and crashes. I don't really care because I don't use MediaPortal, but it prevents me from making a compelling demo video which really sucks after all the work I have put into creating support for this program.
When you are editing actions in the command builder there are popups explaining how the action works and what parameters are expected. You can also click the magic wand icon to browse commands and view explanations. Here you can see that the RequestMusicbySQL action is expecting an "SQL where clause", whereas MpWifi.MvPcFindMovie is expecting "Name of movie to find" for the parameter.
{1} always gets replace by your payload which will be determined by the way your command is defined in the tree, and what you say when you issue the command.
if you have a command where you say "set volume 50", the 50 is probably a payload either defined as a payload list or a payload range. In any case when you put {1} in any of your actions it will be replaced by 50.
The only way I know of now to browse to an artist, would be through a long series of commands that emulate what the user would do to get to the artist. But this is not really possible to do at this point in any kind of reliable way and even if it were it would be slow and kind of silly.