Is it worth taking the time to learn a solo in a song?
ya cause it will show you how to build a solo
depends whether you have found you're own unique sound for solo's yet or not, if you have, then look at the general idea but make up your own, if you haven't then learn it...you should really learn it either way though
Absolutely, 100%. Not only will it help improve your technique, but also your overall songwriting ability.