I'm surprised this feature is overlooked. VB has this and I would certainly love to these these 2 features as well.
Perhaps something like this:
Custom title settings:
Allow this group to use custom titles? [yes][no]
Post required for custom titles: [some_num]
Max char for custom titles: [some_num]
Signature setting:
Allow this group to use signature? [yes][no]
Required post to use signature: [some_num]
Max char for signature: [some_num]
Allow the [color=] tag? [yes][no]
Allow the URL tag? [yes][no]
Allow the image tag? [yes][no]
How many [img] tag for this group? [some_num]
Limit number of lines in signature? [some_num]
There are a lot of forums who have a special group called premium members, and this feature will surely help a lot.