This is not evidence, it is merely your conjecture and opinion. Just because I demand evidence, before blindly believing something someone on the internet says, does not mean I am defending some group - which happens to be another allegation you have made without providing any evidence.
Other than the things mentioned before, another thing Islam teaches is to not make allegations without evidence. Someone can argue that you are quoting Islam in a partial manner; when there is something which supports your opinion you accept it and when it negatively applies to you personally, you might not have found issue with ignoring it.
- "Are Daesh supporters following the Quran? Are they following the hadiths?"
They think they are, or they are following those who manipulate them into believing that they are.
- "Does the Quran forbids killing innocent people? Is there any hadith that allows Muslims to kill innocent people? "
They do not believe their victims to be "innocent".
Tell me, when a Muslim murders, robs, kidnaps, assaults, blackmails or defrauds another person what is your first thought? Is it that, that Muslim must have been paid by some malicious anti-Islamist, atheistic, devil worshipping, entities whose sole purpose in the world is to end the light and righteousness of Islam? I doubt it.
Why is it so difficult to believe that Muslims don't need anyone paying them to kill and maim others? Why is it difficult to believe that Muslims on their own, without any help from any external forces, can be incredibly horrible people too?
Furthermore, while it may be true that the methodology applied by Daesh in pursuit of their objectives is difficult to defend from an Islamic point-of-view, at the same time, it is also difficult to deny that those same objectives parallel the goals of at least some mainstream Muslim scholars. Do you think apostates and blasphemers come under the category of "innocents", a lot of Muslims, although critics of Daesh but similar to Daesh, don't believe so and argue that they should be killed. There are also scholars who believe in the concept of a Global Caliphate and not letting any non-Muslim government to rule, which is purportedly the main objective of Daesh.
Muslims can either continue to believe that they are some special righteous people who are incapable of performing horrible acts (even though they did murder two of the Prophet's successors and his grandson along with his family) and that the real culprits are always some veiled non-Muslims dastardly manipulating events and their outcomes; or they can as a whole accept the high responsibility that Islam puts on them and comprehensively deal, instead of ignoring, the circumstances and faults that allow their religion to be used as justification for these unfortunate incidents.