Some relevant information: I've been playing chess for 4 years, and for 3 in tournaments, although I've only played in about 10 tournaments so far (3 big ones, like the Pan Ams and Chicago Open). My current rating is 1650 UCSF, and my chesstempo rating is 2100, if that is relevant. I'm fairly strong at tactics (and getting away with unsound sacrifices), and decent at positional play (I can recognize the value of controlling dark/light squares, using/creating outposts, securing open files, removing defenders, playing with a space advantage etc).
The Problem: Theory. Although I play the King's Gambit as white, and the Alekhine's Defence/Grunfeld as black, all highly theoretical openings, I don't actually know theory beyond, say 5-8 moves at best. I'm a highly tactical player, so I just seek to create complications from the opening, and end up having a decisive game in the middlegame due to the ensuing fireworks. I've reached the endgame exactly twice so far (out of ~70 games, in tournaments), and hence have very little experience in them. But recently, I've been getting outplayed in the openings, and have decided that its time to man up and learn opening/endgame theory. Since its an arduous task, I request to you, wiser, more experienced players to give me advice on how to fight this monster. Where should I start? Is learning theory just rote memorization? How much is enough (certainly, 8 moves of theory won't do in the King's Gambit or Grunfeld, but may suffice in the Alekhine)?
I've tried to read two books on chess so far: Silman's "Reassess Your Chess", and Taylor's "Alekhine Alert!". While both are highly interesting, I lose patience when they spit out a 50-move continuation after showing an interesting position, and due to not having a board around, I slam the book shut. Do you guys know of any books that don't do that/other resources to help learn theory in an entertaining way?
P.S. I'm very scared of the French and the English because they are highly theoretical, and score very badly against them because I keep trying odd responses (I play the KIA against the French to avoid having my d4 pawn targeted, but get crushed on the queenside anyway, and try the Dutch defence against the English to not lose due to boredom, but lose due to inferior pawn structure (mainly) anyway).