Is this the plan in your opinion?

General
Cost: 3 Level 13: gentle walk
Cost: 8 Level 14: knife
Cost: 8 Level 17: blackjack
Cost: 2 Level 22: doubleback
Cost: 14 Level 25: cheap shot
Cost: 4 Level 27: improved hide
Cost: 39 total

Arcane
Cost: 4 Level 1 : scrolls
Cost: 8 Level 13: arcane lore
Cost: 2 Level 20: glimpse
Cost: 4 Level 27: veil of secrecy
Cost: 7 Level 29: lore of the ages
Cost: 25 total (all nested prereqs)

With 36 points left I pick what? I could drop lore of the ages and get to 43 points but that does not really go that far up any path to get the good skills (3rd attack in thug is one I like). I have not picked some other good skills here (envenom, grapple for example). So you bank on edges to get points? Just trying to figure out how you build a thief around these skills. I agree to large extent on relative worth but the system is stacked that you have to make some trade-offs...