I was just reading up on patch changes and read in the 1.5 patch that viola can be killed without impeading the blood on the ice quests. I haven't been able to continue dark brotherhood for the sole fact I can't get blood on ice to start and trust me I've tried EVERYTHING. So can I kill her now and not have to worry about the mom offing herself? Also I'm on xbox if that makes a difference.

As far as I know, the mom offing herself doesn't make a difference, as the key should be near her body or something.

If she dies you don't get the dialogue options to move on in the quest at least that's how it happened for buddy

I know I am dumb, but I am not that bad, what does Viola have to do with Dark Brotherhood quests? It was Nilsine there was an option to kill for an extra bonus, pretty sure my first character who finished the Dark Brotherhood Quests still has Viola very much alive. But if they made it so you can kill Viola and you really hate her that much go ahead and kill her, the Dark Brotherhood will not be rewarding you for it though. There is no mission to Kill Viola.

Nilsine or Tova should not be essential to do Blood on the Ice, and even Viola is no longer essential, and you should not be able to kill Calixto or Wuunfurth. You do not need the key to Hjerim if your lock picking skills are up to breaking an easy lock, and unless some weird bug ruins the quest Tova's body should still be in the house so you can just go in and get the key if you insist on using the key. But not being able to start Blood on the Ice does sound like there is already a problem.

Are you actually visiting Windhelm at night? You can complete the Blood on the Ice Quest and never speak to any Shatter-Shield, and never use the key to Hjerim. Pretty sure you can complete it by never speaking to Viola, she only points you in the wrong direction anyway.

If you cannot start the quest just start the civil war campaign, you should get the Blood on the Ice quest after they sell you the house.

Patch 1.6 hosed Blood on the Ice for me:

1) The steward refused to sell the house after completing the Civil War questline (first time I experienced this issue)

2) The door to Hjerim is now key-locked (unpickable)

The OP may be experiencing similar problems.

The door to Hjerim has always been key locked till you start the quest and speak to the steward to get permission to investigate the murders, you are then given the choice as to how you get into the house. My last character was started after the 1.5 patch, so if the last patch managed to break the quest, that is unfortunate. It seems more likely though that some other bug that was always there is responsible. If you fight on the Imperial side, you would have to do the usual side quests to be offered the position of Thane, then you can buy the house and become Thane. You do the civil war as a Stormcloak, you should be offered the house before you become Thane.

I saw no dialogue option as a Stormcloak, but maybe you always had to do all the side quests to get the house.

I think your confusing http://www.uesp.net/wiki/Skyrim:Tova_Shatter-Shield with http://www.uesp.net/wiki/Skyrim:Viola_Giordano. Viola has NOTHING TO DO with the Dark Brotherhood absolutely nothing. Toya however may commit suicide if you kill her daughter as part of Muri's DB quest. An optional component whose reward is trivial in most cases. Toya is only needed because Hjerim has a master level lock once you begin Blood on Ice and could be a pain to pick, so getting the key is helpful. However the key can be found on Tova's body which may or may not have been moved to the catacombs.

Buying the house is one of the conditions of becoming Thane.

if the house is key locked then you haven't begun Blood on Ice so you shouldn't get the offer to buy it.

Not true if you complete the Civil War on the Imperial Side, and at that point, getting Blood on the Ice to start normally is a lost cause.