Well that's all awesome if you're on the PC.
Console commands don't work on the uh.... consoles.

Do the Theives guild questline through before the Civil war as well, depending on who you side with it can leave it screwed thanks to a character becoming the Jarl of Riften and you not being able to get the quests from them.
And like someone mentioned, do the Forsworn Conspiracy as well. You can fix the problems it gives you during the MQ or Civil war. Depending on some decisions you make.

Be careful what you do with the Strange Amulet in "Blood on the Ice" quest. I finished the quest eventually after much experimentation, but never got the "real" deal with the Amulet. Just carrying around a useless (now unsellable) quest item labelled "Unusual Amulet" even though the Court Mage told me EXACTLY what it was.

(Because of my own actions probably. Like outdated old fashoned RPG's where you get no where unless you place the feather you found on a fish, on a pole and throw it in the sea -not put the pole on the feather and drop it in the sea. Nor use the feather you found on the monkey burried under the mountain. Then go talk to Mr. "I'm hiding somewhere you never suspected" and tell him what you've done while standing on one leg. -It must be your LEFT leg, even if the game doesn't differentiate, because the quest will not work properly otherwise... be warned and don't complain. You are free to do as you will. And that is what you must do...)

Yeah, at some point someone is supposed to offer to buy the amulet. If you don't sell it, it gets stuck in your inventory.

Odd, I didn't have any issues with Blood on the Ice OR buying a house in Markarth after completing the Mine quest. If anything, that made it easier, since I could just walk through Madanach's hideout without being molested.

The only thing I noticed with Blood on the ice that was odd was that after I completely finished the quest (including chasing down and killing "the real killer" (OJ would be so happy)) was that that last victim was never "cleaned up". Several days later, and her naked corpse is still lying there in the streets.

I guess I've just been lucky.

I would recommend doing the Red Eagle quest not for the sake of any bugs but due to the fact that the sword is not that good once you reach a higher level

A Night To Remember, tried to start this around level 50.

This is the only quest ive had issues with.

• Heres what happened.
  
• 
  
• Spoiler

  
  

  
  
  • After having your third drink with Sam, the screen will sometimes not black
    out and you will not be transported to the Temple, thus rendering the quest
    unobtainable.
  
  
  • The prior bug may encounter another bug that causes Ysolda to die. Upon her
    death, a courier may send an inheritance letter on her behalf with 100 gold
    minus taxes, even if you did not marry her. (PS3)(PC)(Xbox 360)

Another quest that you have to do at least part of at the right time has to do with the odd gems in a box that you find in various locations.
As part of a Thieves Guild quest you have to get all 24 (if memory serves correct) to clean that one up.
The fence woman won't buy just a portion of the gems at a time.
I found out the hard way you need to take the gem located in the Thalmar Embassy while doing that quest line for the Blades.

After doing sneak & peek for the Blades the Thalmar Embassy is locked tight. There are video's on Youtube to show the work around but it appears the intent of the designers is to make the gem inaccessible after that point.

Since the darn things are quest related items you can't get them out of your inventory.

The one time I did Blood On the Ice I got through it with no problems but I'm not willing to risk it again, same for the Louis quest. Also I think Beth fixed this but when you do the Civil War questline do it all at once not one quest and then wait 10 hours to start again.

Forsworn Conspiracy should be avoided like the plague. Just read the note, put it in a random barrel somewhere and ignore it until Beth fixes it.