Windows Explorer 7 command line

How can I make them go away for just this window I'm opening?

I don't really think you can. All the extra stuff in the left-pane is a standard part of the Win7 explorer. Any portions of it that you can turn off are turned off globally for all explorer instances in that user's profile. I don't think there has ever been a supported way to turn off explorer features on a per-instance basis.

You might be able to get down and dirty with window handles and Win32 APIs to tweak or hide the widgets that you don't want seen once you've opened your instance. But I can't really give you any pointers where to begin with that.

AFAIK there's no solution to organizing the Navigation pane per Explorer instance.

Since your wish is to free up space in the pane, the next best thing is to clear out the items that you never use. You can create .reg files to remove or add back these items.

The article Remove Favorites, Libraries, and Homegroup from Navigation Pane shows how you can achieve the following:

Here are the contents for the .reg files that will switch on/off items in the Navigation pane:

Remove Favorites

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{323CA680-C24D-4099-B94D-446DD2D7249E}\ShellFolder]
"Attributes"=dword:a9400100

Restore Favorites

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{323CA680-C24D-4099-B94D-446DD2D7249E}\ShellFolder]
"Attributes"=dword:a0900100

Remove Libraries

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{031E4825-7B94-4dc3-B131-E946B44C8DD5}\ShellFolder]
"Attributes"=dword:b090010d

Restore Libraries

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\CLSID\{031E4825-7B94-4dc3-B131-E946B44C8DD5}\ShellFolder]
"Attributes"=dword:b080010d

To remove Homegroup (and stop Homegroup networking functionality):

1. Go to Control Panel -> Network and Sharing Center -> HomeGroup, and click on Leave the homegroup link to unjoin from any existing home group.
   Note: If the home group are shared and hosted from the PC, all HomeGroup connections will be disconnected.
2. Click on Leave the homegroup and confirm. In the future, if you want to use Homegroup networking you can create a homegroup using this same dialog.
3. Go to Control Panel -> System and Security -> Administrative Tools, and double click on Services. Alternatively, type services.msc in Start Search.
4. For each of the following two services:
   HomeGroup Listener
   HomeGroup Provider
   Do the following:
   Stop the service, and then double click on the service to open Properties dialog, and set its Startup type to Disabled. Click OK when done. In order to reinstate Homegroup functionality in the future, you will want to set the Startup type back to Manual.
5. The HomeGroup icon and group will no longer be shown in the navigation pane of Windows Explorer in Windows 7. Note that this does not interrupt "traditional" windows networking functionality (e.g., Map Network Drive).

Not sure what exactly you really wanted. But I think this will help auto expanding the folder in Windows 7

ps: to enable this go to Tool... > Folder Options and check the expand sub folder. And I guess you get get rid off those that you don't want to see