I've never had a light touch and always admired guys who did. It's so much easier to play relaxed.
Tuning on a fretted instrument is always a compromise--you're never, ever, going to be perfectly in tune. You might try tuning to the nioes you play most often, whatever your playing style is
Yeah, you never know what's "right". I have a buddy in town that ribs me about my "light touch", like it was an affliction
. Mine really isn't so light a touch, and maybe his is "too heavy". If you're playing a bass that won't set up well (i.e. low), then you really have to work too hard, then you lose the character of the tone, and intonation, from beating the hell out of the strings. I've played his Alembic Epic at open mics, and it's like playing an upright- the most exausting electric I've ever played, because of the setup. It doesn't even sound like an Alembic to me because of the action being so high and the heavy string gagues he uses, but he has to set it high because he has a "heavy touch" and heavy strings. It's horrible, and totally against how Mr. W. intended his basses to be setup, IMHO. When I had my Series 1's it was low action, light strings, and a "light touch". Hmm, that sounds like how I set up my Dingwalls. Sheldon has talked about this in the past, IIRC.
I get what you are saying, but I would never tune to fretted notes because it's not a stable frequency due to finger pressure varying. I like the sound of open strings and I use them as much as is practical. True, 99.9% of the notes we play are fretted ones, but if the set up is right (low) and the intonation is set well, then fretted notes will only be a couple of cents off at most -maybe less- not enough to notice.