Yo!
I think what the 'Bard' was talking about, with the precise time kind a thing, was to not spend unnecessary time holding down strings when you don't need the sound of the note any more.
As for deciding which are you going to be, singer our instrumentalist. Don't be held back by any option. Go for it. Playng should never overtake the voice, because the story is more important than the than the book cover. But that doesn't mean to say that the cover shouldn't be tastefully decorated neither.

Bren.