That is only as the Fatwa states in the beginning, you may have overlooked it, that is only when someone commits treason and comes back knowing all about the Muslims position and weak areas to plot to kill them. This is only for treason.

You cannot take the Quran without knowing its Sciences. You cannot take a verse without knowing, when it was revealed and what it was talking about. You cannot make up your own assertions either. Likewise you cannot know certain ahadith without a scholars commentary and further study.

At the time these verse were revealed, there were hypocrits among the Last prophet ( pagan Arabs ) and they would say they were Muslim and eat, live, drink with them. They would find out details and weaknesses and news etc only to leave to get other Pagan Arab tribes in on killing them. Muhammed had many enemies. Just as Jesus, peace be upon him had ( the governing elite ). The Jews and pagan Arabs wanted him dead and the call to God's Oneness quieted. The Pagan Arabs had a idol for everyday of the year which they worshipped along with the One God. They were not about to destroy what their fathers had done and wanted to keep things the way they were.

So these verses pertain to the ones who were committing terrible acts of treason and Terrorism on the new followers and leaders of Islam. They ( the followers ) were already being tortured and killed ( by the Arab tribes ) for not praying to the false gods and Idols as the governing elite wanted. Great sacrifices were being made just to follow the Last Prophet. You must understand this.

Again, Verses from the Holy Quran tell it plainly:
Translation to English:

[There shall be no compulsion in religion. Distinct has now become the right way from [the way of] error: hence, he who rejects the powers of evil and believes in God has indeed taken hold of a support most unfailing, which shall never give way: for God is all-hearing, all-knowing] ( Al-Baqarah ( The Cattle 2:256)

[If it had been your Lord's will, all who are in the earth would have believed. Will you, then, force the people to become believers?] (Yunus ( Jonah 10:99)

[And if they surrender themselves unto Him (i.e. God), they are on the right path; but if they turn away – behold, thy duty (O Muhammad,) is no more than to deliver the message: for God sees all that is in [the hearts of] His creatures.] (Aal `Imran ( Family of Imran 3:20)

[Hence, pay heed unto God, and pay heed unto the Messenger, and be ever on your guard [against evil]; and if you turn away, then know that Our Messenger's only duty is a clear delivery of the message [entrusted to him].] (Al-Ma'idah The Table Spread from Heaven 5:92)

[But if they turn away [from thee, O Prophet, know that] Wehave not sent thee to be their keeper: thou art not bound to do more than deliver the message [entrusted to thee] .] (Ash-Shura (The Council 42:48)

I should further state that all of the moral teachings of the Qur'an are based on the notion of moral responsibility, which entails the freedom of choice. Therefore, to state that one must be put to death for choosing to disbelieve would only undermine the entire moral edifice of the Qur'an.

Furthermore, the Qur'an does not allow anyone to harm those who are leaving in peace, no matter what religion they hold on to. This principle has been clearly stated in the Qur'an as follows:

[Thus, if they let you be, and do not make war on you, and offer you peace, God does not allow you to harm them.] (An-Nisaa'( The Women 4:90)

In pursuance of this policy, the Prophet (peace and blessings be upon him) issued clear directives to his soldiers never to disturb those who are engaged in any form of worship. The policy of living and letting others to live is firmly enshrined in the following verses:

[Say: O disbelievers! I do not worship what you worship, Nordo you worship what I worship. ... to you your religion, and to me, mine.] (Al-Kafirun ( The Disbelievers109:1-3, 6)

In full conformity with the above teachings, neither the Prophet (peace and blessings be upon him) nor any of the four rightly guided caliphs who succeeded him were in the habit of hunting down people and executing them for merely changing their religions. Rather, they refrained from doing so except in rare cases involving treason. Treason, however, is another matter. The punishment for treason in the Qur'an is as strict as it is in the Hebrew Bible. But it must never be confused with mere change of religion.

In conclusion, it is absurd for anyone to suggest that Islam advocates killing people who covert to another religion.