dont let the chord guide u guide thru the chord find the intervals that go well with the chords and use them for expression. if u have an idea dont stop going up the neck keep going. most guitarists will stop and find there comfort zone u gotta keep going up if u have an idea just keep going doesnt matter what key as long as the intervals fit with the chords. say if u have a pentatonic lick with some hammers and pull ofs u do that in the obvious key lets say the fist chord was g do the petnatonic lick in g then find the intervals that fit with the chords and keep going with the same lick. in every interval
i hope that makes sense. now for using modes ur job as a guitarist is to make the listener exposed to new ideas with the melody. so basically when ur in a band u want to take them on a journey. decide which note u wanna start with and end with and flow inbetween.
hope it all makes sense.