Once again you used the same website which will never promote Islam. If you think these extreme Christians are playing fair games, you are mistaken. They are taking verses from Quran and commentary from Muslim scholar to twist the facts and present them is a way which promotes their agenda.
Imam al-Qurtubi says:
"It is essential to understand the question of abrogation, and great benefits flow from such an understanding, which no scholar can dispense with, and no one can deny abrogation except the ignorant and the dull-headed."
Is that guy calling you names? They look like Islamic sources to me. Now you can tell me why they are not.
One of your quote (I quoted above) from Imam Al Qurtabi points out to benefits of abrogation. Let me explain with a simple example abrogation and how it actually proves that Islam is the only true religion.
Alcohol was prohibited in four different stages in Quran:
It was originally permissible.
Then it was discouraged by verse 2:219.
Then it was prohibited to drink before prayer by verse 4:43.
Then it was prohibited in general by verse 5:90.
There are important lessons to be learned from this experience of gradual prohibition. At the beginning stages of the Prophet Muhammad PBUH's mission, people were simply not ready to give up alcohol for the sake of a greater purpose. Aisha (ra) said, “If the first thing to be revealed was ‘Do not drink wine,’ they would have said, ‘We will never stop drinking wine.’ And if it were revealed ‘Do not commit adultery,’ they would have said, ‘We will never stop committing adultery.’” Certainly, alcohol can have such a tight grip over people’s lives that only strengthening their faith can break it. Even today, the successful Alcoholics Anonymous 12-step program makes explicit references to God as the reason and means to quit. Likewise, people at the time of the Prophet Muhammad PBUH needed to build up their faith and recognize a meaningful purpose to their lives that would make the difficult struggle of quitting alcohol worth it. The same model of gradual, progressive implementation on a societal level can apply to other Islamic teachings as well.
None of the verse is abrogated. All these verses are still in Quran and these are there for our guidance. For example in case of Alcohol, general rule is that it is not allowed to drink alcohol. However, if a non-Muslim accepts Islam and is addicted to alcohol, then we apply the same rule of gradual prohibition. Same goes with reading five prayers which are obligatory on Muslims but for a new Muslim it is allowed to slowly start praying ( pray one prayer a day and slowly build up). It is most natural way. You don't go to gym and start lifting 200 lbs, it takes time to build up yourself and if one remains consistent then one day he/she can lift heavy weights. On the other hand if one starts lifting heavy weights from day one, most likely they will never come to gym after 2/3 days.
I really hope that you read this with an open mind. This is why it is important to seek knowledge from those who know ( Muslim scholars not the Christian so called scholars).