Ok, we've got the idea.
The real issue here is not only to do the coding, but also to define a simple & consistant syntax.
In the following beta, we have introduced a new skinparam padding:
For example, you can use:
skinparam padding 10
Note that this is really temporary : we are not sure that adding such a parameter is a good idea.
The main issue here is that this parameter is global : it changes padding everywhere.
And to us, having specific parameters for members, classes, labels... would be too complex for the end user.
(There are already too many XXXColor, XXXFontSize params).
Another possibility would have to have some specific syntax in the creole parser itself, but it would mean that you'll have to repeat your setting on every label.
Anyway, the goal of this beta is to let you play with it, to see if other/better ideas will emerge :-)
Thanks again for your suggestions!