Did not know that about killing Astid :P I usally killed all the prisoners, saved, and them murdered Astrid :P

I would chose DB anyway becuase of some nice quests and rewards

I want the chameleon enchant back from Oblivion. I missed making a set of 100% chameleon equipment and breezing through the Thieve's Guild Questline

(For the uninitioned, Chameleon is basically weak invisablity that doesn't dispel when you perform an action.)

Pre-patch there is an exploit near Azuras Shrine, the Book glitch.

http://www.youtube.com/watch?v=_Sp71Is2S98

The patch allows you to do this exactly once and then the skeleton disappears for good. I'd say delete the updates, start a new game, grab a follower, make the trip and grab as many books as you can.

Otherwise, smith alot of Iron Daggers and enchant all of them with paralze and sell them. Best ways IMO

Idont think there is actually a way to destroy the Brotherhood, I never got the option. You get a butt load of gold for finishing off the DB questline so I would say go with that

I have this problem as well. The option to ask the Jarl for work never appears for me. Before the updates (I hadn't played Skyrim in 2 months) I was able to get the questline started rather easily. I have now completed the Thieves Guild and tried pretty much all the quests, nada.

Maybe try clearing your cache (erasing the updates) and trying? Might work. Might cause an error where it says "This is a save with an update and can't be played without it" or something like that.

If you don't know how to clear your cache I made a tutorial on it: http://www.youtube.com/watch?v=i5zXCVy_jOA&feature=BFa&list=PL624F29BFB83024DF

ifyou already know the quest you should be able to start it without hearing the rumor. That goes for any quest. I usually pick up Azura's Star by visiting the Shrine of Azura before hearing it from anyone.

Otherwise I don't know, I only know a couple of the Daedric quests

As far as unique weapons (named ones) I have no clue. All weapons are tiered based on the material used in them.

In order: 

Iron 

Steel

Orcish

Elven

Dwarven

Glass

Ebony

Daedric 

So the best warhammer in the game would be a Daedric warhammer but those aren't dropped by enemies, just found in chests. Daedric weapons though are extremely rare. You can smith one with the proper perks and a smithing skill of 90 or higher. Otherwise go with an Ebony warhammer