(2) come in handy: to be useful fret about: worry about, be anxious subtle: not very noticeable underwrite: support, sponsor, pay for
(3) adopt: embrace contend with: cope with resort to: have recourse to nuance: slight difference, fine distinction ambiguous: unclear, equivocal Mumbo jumbo: nonsence muddy the water: make a smple situation confused/more complicated than it really is
"Nuance may be misinterpreted or not understood, to mutual confusion." の意味の感じがなんとなくよくわからないです。ま、いっか。
(4) preclude: prevent, make it impossible, rule out laggard: slow and/or lazy person/organization, straggler