Hunter main here. Part of the joy of gear progression is that, as you get higher ilvl gear, you find single pieces with more and more hit (which I agree is a great mini-game to balance) so you go from needing +hit on almost every piece of gear down to 3 or 4 pieces with +hit and maybe an enchant or gem or two.

As to expertise vs hit, and their value as stats, you have to think of an MMO like WoW as sort of an automated RPG insofar as all of the "rolling" in combat is handled by the game engine. The game's fight mechanics are carefully designed to draw from pen-and-paper RPG mechanics which are designed to mimic "real life" combat.

Hit can be equated to an extension of weapon skill. The skill cap represents an average degree of proficiency with a weapon and +hit represents a heightened ability not to miss with that weapon. As nothing can happen to a target if you miss, the hit/no hit "roll" happens first, making hit the most valuable stat point for point until you're hit capped.

Expertise represents a degree of skill in melee combat; fancy footwork and the like. When the lvl83 booger-eater you're trying to perforate starts dancing around, can you dance with him and keep from being dodged or blocked (or parried as a tank)? On that note, parries serve as an important mechanic in tanking because it allows for your tank to take a double-hit and, if he's not geared enough or the healers aren't on the ball, he can get gibbed.

As for understanding more about how all of these stats impact you as a hunter, check out the forums at Elitist Jerks, use Shandara's spreadsheet or the web version at femaledwarf.com. THEN get Pawn and use the string that you get from femaledwarf to get pawn to accurately represent the values of stats based on what you have/need and give you a rough estimate of the value of different items.