Richard Bridge .That is a very good idea for deciding string height at the nut.Yes ,some people will make a rattle when others do not .but when you get into the department of guitars that are setup to close tolerances .you tend to see people try harder to play more lightly at times.I have tried to play the strings closer to the saddle sometimes with my strumming /picking hand .Sometimes after you have lowered the nut ,that can improve the sound because the strings have less bend in them as you push down at the fret.so sometimes you learn to push the strings down closer to the fret and push down with less effort .Even with guitars with a low action you can still strum strongly.But articulations require a bit more thought .unless you are one the really great players.It is a tempo thing you can have agressive passages followed by a more steady phrase concentrating more on the value of each note played in a passage .But the value of each note should not really be under evaluated.Because i say this does not mean i think i am a good player .Simon Shaw