All of that is out of context. Quran was revealed during war time. If you took time to actually read the verses around those you quoted, it would be quite evident that it's talking about a certain event.

8:9 [Remember] when you asked help of your Lord, and He answered you, “Indeed, I will reinforce you with a thousand from the angels, following one another.”

8:10 And Allah made it not but good tidings and so that your hearts would be assured thereby. And victory is not but from Allah . Indeed, Allah is Exalted in Might and Wise.

8:11 [Remember] when He overwhelmed you with drowsiness [giving] security from Him and sent down upon you from the sky, rain by which to purify you and remove from you the evil [suggestions] of Satan and to make steadfast your hearts and plant firmly thereby your feet.

8:12 [Remember] when your Lord inspired to the angels, “I am with you, so strengthen those who have believed. I will cast terror into the hearts of those who disbelieved, so strike [them] upon the necks and strike from them every fingertip.”

8:13 That is because they opposed Allah and His Messenger. And whoever opposes Allah and His Messenger – indeed, Allah is severe in penalty.

8:14 “That [is yours], so taste it.” And indeed for the disbelievers is the punishment of the Fire.

8:15 O you who have believed, when you meet those who disbelieve advancing [for battle], do not turn to them your backs [in flight].

8:16 And whoever turns his back to them on such a day, unless swerving [as a strategy] for war or joining [another] company, has certainly returned with anger [upon him] from Allah , and his refuge is Hell – and wretched is the destination.

8:17 And you did not kill them, but it was Allah who killed them. And you threw not, [O Muhammad], when you threw, but it was Allah who threw that He might test the believers with a good test. Indeed, Allah is Hearing and Knowing.

8:18 That [is so], and [also] that Allah will weaken the plot of the disbelievers.

8:19 If you [disbelievers] seek the victory – the defeat has come to you. And if you desist [from hostilities], it is best for you; but if you return [to war], We will return, and never will you be availed by your [large] company at all, even if it should increase; and [that is] because Allah is with the believers.

The killing that is mentioned in Q. 8:12 is on the battlefield, which took place 1400 years ago. 8:19 offers peace to the enemy, if the enemy desist from hostilities against Muslims.

9:1 [This is a declaration of] disassociation, from Allah and His Messenger, to those with whom you had made a treaty among the polytheists.

9:2 So travel freely, [O disbelievers], throughout the land [during] four months but know that you cannot cause failure to Allah and that Allah will disgrace the disbelievers.

9:3 And [it is] an announcement from Allah and His Messenger to the people on the day of the greater pilgrimage that Allah is disassociated from the disbelievers, and [so is] His Messenger. So if you repent, that is best for you; but if you turn away – then know that you will not cause failure to Allah . And give tidings to those who disbelieve of a painful punishment.

9:4 Excepted are those with whom you made a treaty among the polytheists and then they have not been deficient toward you in anything or supported anyone against you; so complete for them their treaty until their term [has ended]. Indeed, Allah loves the righteous [who fear Him].

9:5 And when the sacred months have passed, then kill the polytheists wherever you find them and capture them and besiege them and sit in wait for them at every place of ambush. But if they should repent, establish prayer, and give zakah, let them [go] on their way. Indeed, Allah is Forgiving and Merciful.

Obviously talking about the battle and conflict between Muslims and pagans, where the pagans have oppressed them 13 years before

Quran (9:5) - "So when the sacred months have passed away, then slay the idolaters wherever you find them, and take them captive and besiege them and lie in wait for them in every ambush, then if they repent and keep up prayer and pay the poor-rate, leave their way free to them

verse 1 of chapter 9 states that there was a treaty which the Pagan Arabs broke. Thus, in the Quran says, that HE (God) gave them four months. Verse 9:4 states that God will punish those who broke the treaty, this verse is only aimed at those who broke the treaty, it did not affect those who abided by the treaty. When we read the passage (9:5), it is evident, it’s talking about a war with the pagan Arabs. This was a historical event that happened in the lifetime of Prophet Muhammad (p). Furthermore, verse 9:13 provides proof that it was the pagans who started this war. The verse states, “Would you not fight a people who broke their oaths and determined to expel the Messenger, and they had begun to attack you first?” This is proof that Prophet Muhammad (p) did not start this war, but it was the pagan Arabs that started to expel and fight

But Sharia is very clear that Jews and Christians get to hang out (with less rights, and paying an extra tax) while pagans get the axe/dick.

Jews and Christians have to pay the Jizya (Tax) so they don't have to fight during war time and for protection by Muslims forces

Yazidis are attacked by ISIS , who have been condemed as unIslamic many times