I just found out how to lay out submorphs using layoutFrame and
LayoutPolicy. 

If all I want is a submorph that is inset by a number of pixels and
whose size follows the size of its owner, do i still need a
LayoutFrame or is there an easier way ?

I sortof don't know where to send the methods I sent to LayoutFrame,
you know this kind of stuff:
(topOffset:10; bottomOffset: -10; leftOffset:10; rightOffset: -10;
topFraction:0; bottomFraction:1; leftFraction:0; rightFraction:1.)