[TYPO3-dev] SysFolder, Contains Plugin, $ICON_TYPES

[Uschi Renziehausen]

Happy New Year to all,

I would like to modify the items in the list that shows up under Contains Plugin which in itself should not be a problem. Of course I would like to have special icons for my SysFolders if they e.g. 
contain the plugin Acronym. Reading the Core Api [1] I found out that this is done with the global array $ICON_TYPES. Unfortunately the documentation also says that the usage of that array is 
deprecated. So here my questions:

1) Is there an alternative way to get a special icon for SysFolder with field module set to x? If so, can you point me into the right direction?
2) If not, for how long will it be safe to use $ICON_TYPES?
3) Can I ensure somehow that for a SysFolder with the e.g. value news only News Items will be allowed?

Kind regards, Uschi