Michael, this may sound odd for some situations but I was trying to think of this working..

Having the trim and boolean/extrusion commands work in the same manner as sweep, with regard to the ability to create curves outside of the bounds or actual placement of the profile..

It seems like it could create a nice workflow (as opposed to really adding anything you cant already do now)

So like if you need to cut 3 .5 holes, instead of drawing the 3 holes and doing the boolean diff, you could just select 1 hole drawn off to the side, then perform the boolean diff by defining the placment with some picks.. (Direction would come from viewport) This could work with various extrusions and stuff also..

Is this command workflow available to the boolean/trim/extrusion with 2d curves?