I was wondering if it is possible to eventually, through continued play and what not, to get ALL of a character's skills up to the maximum level, including health, energy, etc. Otherwise I need to start devoting points only to my treasured skills, but I am hoping not.
I'm not leaving this place/ unless i'm leaving with you
It is definitely possible because you can replay the game as many times as you want.
If you're looking to build up one or two people, than it's a feasible option.
If you're looking to build up anymore than that to all 7's, you might wanna consider the boost cheat. It doesn't give you anything you couldn't earn on your own, and saves countless hours. Have a life and use the boost, but that's just my opinion.
I'm the fastest man alive. You're the slowest gamer ever!
-The Flash in JLH.
Realistically: No. It's not possible to get all sevens for everyone. Even on the higher difficulties, high level boosts are dropped far too rarely. You *could* but you'd probably need to play through hundreds of times.
I would also suggest just using the boost cheat once you get to Level 20. It really does make it much more enjoyable.