Regarding dynamics

I realize this topic has received much discussion in the past, but I raise it again to stress its importance.

Presently dynamics are associated with a location within a measure. However, this limits considerably what can be done to make output sound more like real music rather than having a piano roll quality.

What would really be nice is to have an ability to associate dynamics with a note or notes of a particular staff or voice.

And while I'm at it, it would be nice to have an ability to control how much stress a tenuto or marcato dynamic places of the note being modified. Something like a tenuto is to be given a 25% increase in volume, marcato 40%, or some such.