Quraan on Blasphemy

The most consistent theme in Quraan is - no aggression. You shall not mess things and get caught in the whole ball of wax,  but you have a right to defend yourselves. God's wisdom surfaces consistently through a variety of messengers including Jesus and Muhammad - do not aggravate the conflict, i.e., turn the other cheek to sustain the peace. 

Those of you who do not believe in the fire, hell, brimstone etc, take is as the anguish and turmoil within the soul.

Muhammad Irtaza has compiled several verses below and I have added Asad's translation where needed to ensure checks and balances.  

I urge you to do your own versification, finding the truth is your own responsibility. 

The Messenger of God Muhammad delivered the following messages on the Blasphemy Laws:
  
4:140 (Asad) And, indeed, He has enjoined upon you in this divine writ that whenever you hear people deny the truth of God's messages and mock at them, you shall avoid their company until they begin to talk of other things   [ Lit., "you shall not sit with them until they immerse themselves in talk other than this".]  - or else, verily, you will become like them. Behold, together with those who deny the truth God will gather in hell the hypocrites.

5:57 (Asad) O you who have attained to faith! Do not take for your friends such as mock at your, faith and make a jest of it-be they from among those who have been vouchsafed revelation before your time, or [from among] those who deny the truth [of revelation as such] -but remain conscious of God, if you are [truly] believers:

[6:68] If you see those who mock our revelations, you shall avoid them until they delve into another subject. If the devil causes you to forget, then, as soon as you remember, do not sit with such evil people.

[18:106] Their just requital is Hell, in return for their disbelief, and for mocking My revelations and My messengers.

[39:48] The sinful works they had earned will be shown to them, and the very things they used to mock will come back to haunt them.

[45:33] The evils of their works will become evident to them, and the very things they mocked will come back and haunt them.

Why the Muslim masses ignore the Messenger Muhammad?  Who they want to please?

The punishment is delivered by God, not by you or me.

The killing is justified only if  people wage  war against you. You may kill them, in that case:

[5:33] (Asad) It is but a just recompense for those who make war on God and His apostle, ^[43] and endeavour to spread corruption on earth, that they are being slain in great' numbers, or crucified in great numbers, or have, in l' result of their perverseness, their hands and feet cut off in great numbers, ^[44] or are being [entirely] banished from [the face of] the earth: such is their ignominy in this world . ^[45] But in the life to come [yet more] awesome suffering awaits them


43- The term "apostle" is evidently generic in this context. By "making war on God and His apostle" is meant a hostile opposition to, and wilful disregard of, the ethical precepts ordained by God and explained by all His apostles, combined with the conscious endeavour to destroy or undermine other people's belief in God as well

44- In classical Arabic idiom, the "cutting off of one's hands and feet" is often synonymous with "destroying one's power", and it is possibly in this sense that the expression has been used here. Alternatively, it might denote "being mutilated", both physically and metaphorically -similar to the (metonymical) use of the expression "being crucified" in the sense of "being tortured". The phrase min khilaf-usually rendered as "from opposite sides"-is derived from the verb khalafahu, "he disagreed with him", or "opposed him", or "acted contrarily to him": consequently, the primary meaning of min khilaf is "in result of contrariness" or "of perverseness"

The killing is not justified if people evict you. You may only evict them:

[2:191] You may kill those who wage war against you, and you may evict them whence they evicted you. Oppression is worse than murder. Do not fight them at the Sacred Masjid, unless they attack you therein. If they attack you, you may kill them. This is the just retribution for those disbelievers.

The killing is not justified if people insult the Prophet. God will take care of it. 

[18:106] Their just requital is Hell, in return for their disbelief, and for mocking My revelations and My messengers

And, these are some of the Quranic wisdoms:

[42:37] They avoid gross sins and vice, and when angered they forgive

[42:40] Although the just requital for an injustice is an equivalent retribution, those who pardon and maintain righteousness are rewarded by GOD. He does not love the unjust.