i'd say do whatever makes you enjoy it and whatever works for you. everyone is different, and enjoying it is half the battle.
don't listen to (no-one here is saying this) the people who act like you're awful if you're not practising for 8 hours a day, or that "playing stuff you know isn't practising". Playing is better than not playing, and if you only practise exercises that's a pretty quick route to sounding unmusical, imo. You're playing for you, not these other people, and if you want to play for 10 minutes a week, that's absolutely fair enough.
also, "talent borrows, genius steals". if you hear something good, shamelessly nick it. :lol: If you nick from enough players, you'll start to have your own style. :lol:
I've often thought: we've only ever really heard Tony Iommi play Sabbath songs, or Angus Young play AC/DC.... we love 'em, and think of them as great players, but what if that's all they really can play, their own songs and nothing else? They'd actually be pretty limited.*
that's a good point. I listen to killer players and get demoralised, "Oh i wish i could do legato like satriani, sweep like malmsteen or tap like vai", but (maybe) vai can't do legato like satriani and malmsteen can't tap like vai. (of course, they probably can, but it's still worth bearing in mind.)