The messengers are below him just like us, we cannot ask them to do anything for us, because they are not our owner! See:2-107

أَلَمۡ تَعۡلَمۡ أَنَّ ٱللَّهَ لَهُ ۥ مُلۡكُ ٱلسَّمَـٰوَٲتِ وَٱلۡأَرۡضِ‌ۗ وَمَا لَڪُم مِّن دُونِ ٱللَّهِ مِن وَلِىٍّ۬ وَلَا نَصِيرٍ (١٠٧) أَمۡ تُرِيدُونَ أَن تَسۡـَٔلُواْ رَسُولَكُمۡ كَمَا سُٮِٕلَ مُوسَىٰ مِن قَبۡلُ‌ۗ وَمَن يَتَبَدَّلِ ٱلۡڪُفۡرَ بِٱلۡإِيمَـٰنِ فَقَدۡ ضَلَّ سَوَآءَ ٱلسَّبِيلِ (١٠٨)

Knowest thou not that it is Allah unto Whom belongeth the Sovereignty of the heavens and the earth; and ye have not, beside Allah, any friend or helper? (107) Or would ye ask your messenger as Moses was asked aforetime? He who chooseth disbelief instead of faith, verily he hath gone astray from a plain road. (108)

وَٱلَّذِينَ تَدۡعُونَ مِن دُونِهِۦ لَا يَسۡتَطِيعُونَ نَصۡرَڪُمۡ وَلَآ أَنفُسَہُمۡ يَنصُرُونَ (١٩٧)

They on whom ye call beside Him have no power to help you, nor can they help you, nor can they help themselves. (197)

قُلْ إِنَّمَا أَنَا بَشَرٌ مِّثْلُكُمْ يُوحَى إِلَيَّ أَنَّمَا إِلَهُكُمْ إِلَهٌ وَاحِدٌ فَمَن كَانَ يَرْجُو لِقَاء رَبِّهِ فَلْيَعْمَلْ عَمَلًا صَالِحًا وَلَا يُشْرِكْ بِعِبَادَةِ رَبِّهِ أَحَدًا ﴿۱۱۰﴾

 following the prophets means following the created human.

Not at all. God again continually says that the prophets should be followed, have you not read Quran carefully:

Quran (3:31-32)

(31) Say: If you love Allah, then follow me, Allah will love you and forgive you your faults And Allah is Forgiving, Merciful.
(32) Say: Obey Allah and the Messenger But if they turn back, then surely Allah does not love the unbelievers.
قُلۡ إِن كُنتُمۡ تُحِبُّونَ ٱللَّهَ فَٱتَّبِعُونِى يُحۡبِبۡكُمُ ٱللَّهُ وَيَغۡفِرۡ لَكُمۡ ذُنُوبَكُمۡ‌ۗ وَٱللَّهُ غَفُورٌ۬ رَّحِيمٌ۬ (٣١) قُلۡ أَطِيعُواْ ٱللَّهَ وَٱلرَّسُولَ‌ۖ فَإِن تَوَلَّوۡاْ فَإِنَّ ٱللَّهَ لَا يُحِبُّ ٱلۡكَـٰفِرِينَ (٣٢)

It is not following him, this is Obey from his commands which are words of Allah. Quran 3-143

وَمَا مُحَمَّدٌ إِلَّا رَسُولٌ۬ قَدۡ خَلَتۡ مِن قَبۡلِهِ ٱلرُّسُلُ‌ۚ أَفَإِيْن مَّاتَ أَوۡ قُتِلَ ٱنقَلَبۡتُمۡ عَلَىٰٓ أَعۡقَـٰبِكُمۡ‌ۚ وَمَن يَنقَلِبۡ عَلَىٰ عَقِبَيۡهِ فَلَن يَضُرَّ ٱللَّهَ شَيۡـًٔ۬ا‌ۗ وَسَيَجۡزِى ٱللَّهُ ٱلشَّـٰڪِرِينَ (١٤٤)  

Muhammad is but a messenger, messengers (the like of whom) have passed away before him. Will it be that, when he dieth or is slain, ye will turn back on your heels? He who turneth back on doth no hurt to Allah, and Allah will reward the thankful. (144)

Means following the messenger, if is different from following the Lord, will be up to the death of that messenger! Yes?! The reason is here: 3-79

مَا كَانَ لِبَشَرٍ أَن يُؤۡتِيَهُ ٱللَّهُ ٱلۡكِتَـٰبَ وَٱلۡحُكۡمَ وَٱلنُّبُوَّةَ ثُمَّ يَقُولَ لِلنَّاسِ كُونُواْ عِبَادً۬ا لِّى مِن دُونِ ٱللَّهِ وَلَـٰكِن كُونُواْ رَبَّـٰنِيِّـۧنَ بِمَا كُنتُمۡ تُعَلِّمُونَ ٱلۡكِتَـٰبَ وَبِمَا كُنتُمۡ تَدۡرُسُونَ (٧٩)

It is not (possible) for any human being unto whom Allah had given the Scripture and wisdom and the prophethood that he should afterwards have said unto mankind: Be servants of me instead of Allah; but (what he said was): Be ye faithful servants of the Lord by virtue of your constant teaching of the Scripture and of your constant study thereof. (79)

On the other hand you want follow someone who does not know anything about the invisible world and cannot does anything even for himself?!! And you want him do something for you?!! Up to you , but he say himself something else : 7-188

قُل لَّآ أَمۡلِكُ لِنَفۡسِى نَفۡعً۬ا وَلَا ضَرًّا إِلَّا مَا شَآءَ ٱللَّهُ‌ۚ وَلَوۡ كُنتُ أَعۡلَمُ ٱلۡغَيۡبَ لَٱسۡتَڪۡثَرۡتُ مِنَ ٱلۡخَيۡرِ وَمَا مَسَّنِىَ ٱلسُّوٓءُ‌ۚ إِنۡ أَنَا۟ إِلَّا نَذِيرٌ۬ وَبَشِيرٌ۬ لِّقَوۡمٍ۬ يُؤۡمِنُونَ (١٨٨)

Say: For myself I have no power to benefit, nor power to hurt, save that which Allah willeth. Had I knowledge of the Unseen, I should have abundance of wealth, and adversity would not touch me. I am but a warner, and a bearer of good tidings unto folk who believe. (188)

...........Quran reveal for us a mistake of Muhammad( that for him is completely as a sin!)

Unfortunately, you are misinterpreting Quran (66:1). First of all, this is not a sin. The prophet already had the complete free will (from God) to whether act to a Hallal in his personal and private life or not. Accordingly he decided to ban a Hallal thing in his private life to satisfy one or more of his wives. Secondly, as soon as God told him not to do so the prophet broke the ban and therfore, he followed God in both cases. Not a sin nor even a moment of disobeying happened for the prophet.

A sin for a prophet is not as a sin for other people. Because he is blessed and is walking with God, then he has to do every thing to make God happy .

يَـٰٓأَيُّہَا ٱلنَّبِىُّ لِمَ تُحَرِّمُ مَآ أَحَلَّ ٱللَّهُ لَكَ‌ۖ تَبۡتَغِى مَرۡضَاتَ أَزۡوَٲجِكَ‌ۚ وَٱللَّهُ غَفُورٌ۬ رَّحِيمٌ۬ (١

O Prophet! Why bannest thou that which Allah hath made lawful for thee, seeking to please thy wives? And Allah is Forgiving, Merciful. (1)

Muhammad is not a sinner any more. But these 2 acts are his sins:

1-    bannest that which Allah had made lawful

2-    seeking to please of human , not please of God

This is the message of Quran in the first verse of this chapter that Muhammad without God, is a simple sinner human, he will do mistake every time he forget to please God instead of human, he will do the same mistakes as me do and you do.

Then lets don`t look at him just like a supper human that was cleansed from the first (!!!) and on the other hand, don`t forget his friendship with God and the mission that he had from him and how he did that as well as he could do.