Good afternoon, everyone! I'll waste no time trying desperately to be funny today, we'll just jump into this thing.
Which heroic dungeon provides the most rep? Of course, this will probably vary depending on the amount of trash pulled (full clear vs. "just the pats, ma'am"), but accounting for bosses and essential trash pulls, where can I farm to max out my rep as quickly as I can?
Wowwiki has a pretty good list of this on their Championing page. It's missing data for a few dungeons and might not be 100% accurate, but it lists The Nexus and Ahn'kahet as the Heroics with the highest reputation potential in a single run. Violet Hold and Azjol-Nerub are listed as having the lowest possible rep per run, but they're also very, very fast dungeons.
There aren't very huge divides in how much you gain where, they're all rather close to one another. If you ignore the two really short ones, all of the others are within roughly 300 reputation of each other. The list over on Wowwiki will help you maximize your gains if you want, but I think that in the end you'll feel better about the grind if you just run whichever Heroics you like.
I know I could just try Wowhead but incase they come up short is there a way I can find the quatermasters for each faction?
Wowhead will work just fine for this, they have absolutely all of them listed with their locations. If you really want a backup, we've written a very basic overview of Wrath reputations that list the towns with Quartermasters.
Why is Anub'arak simply a 5-man boss fairly early in the expansion? Pretty much all of the other NPC's that played a role in WarCraft 3 appear as raid bosses and usually the last boss of a raid at that.
In Wrath of the Lich King they tried to make lore characters a lot more accessible to players, and while I can't say it with certainty, I suspect Anub'arak was their first attempt at that while building the expansion. It's a little disappointing that he didn't have a larger presence, and Azjol-Nerub overall could've used a lot more love.
I don't think a major lore figure needs to be a raid boss, but I do agree that they should've done more with Anub'arak. Were Azjol-Nerub a level 80 dungeon, perhaps they would have had more time to add more to his character, but maybe not. Overall, I don't really know why they did what they did and all that we can do is speculate. I agree that he should have had more of a role though, even if it were only a single quest chain that both factions could get.
What I don't understand is with such a nice and fancy new harbor in Stormwind, would it have been such a bad idea to open up one simple bar?! I mean, really...what's the docks without a bar!
Improvise! Hop up into one of the docked boats, and make a themed bar! Just make sure to bring the booze with you, because you'll feel a bit silly if you sneak up there and find yourself dry.