The Quran says:
1) all things are created in pairs
2) the sun sets in water on the Earth.
3) stars are missiles against Devils
4) mountains were put in place to stop the Earth from shaking.
5) the Earth is spread out like a carpet.
6) the Earth was created before the heavens
7) the sun runs to a resting place
I'd say they were pretty major errors, what's more is they are all in line with the scientific knowledge of the time, more proof the Quran was written by men.
1. Pairs
We constructed the universe with might, and We are expanding it. The earth We furnished; We are fine Providers. From everything We created a pair, perhaps you may remember. So turn towards God. I am to you from Him a clear warner. 51:47 - 50 Quran.
What really is the problem there? It says the universe is expanding and that everything was created in pairs. We know that the universe is expanding, also we know that there are pairs of everything. Maybe you understood pairs as two (2). Thats not exactly true. It is Zawj, Azwaja. Means a pair like a couple. Male and female or married. Stones get married, but you understand what I say. There are other verses that refer to plants specifically. We know that plants are male and female.
2. Sunset.
Is it because the verse says "Setting of the Sun" that you have a problem with? It does not say the Sun sets in water. It says that he reached the Sunset, then he reached the Sunrise a couple of verses later. Have you heard of the evening prayer that Muslims generally refer to? Maghrib. This is the same. l Maghribi is the west.
Whats said is that he went hither and thither.
3. Stars are missiles against devils
See, the Quran does not say missiles. Nor does it say that stars are thworn. I believe Yusuf Ali translated it that way. There is no way.
The Quran has As-Shaythan and Shaythan. Shaithan could mean Astray. The verses you refer to talk about Rebellious Shaithanin.
Kawkab has been translated as stars or planets. At the outset of the verse, it does not have any issue. "We have adorned the lower heaven with the decoration of planets" and next verse simply says "And to guard against every rebellious Shaithanin (Astray)".
4. Mountains act as pins that two plates of the earth together. But I would like to know what your idea about this is for you to cite this.
5. Where does it say carpet? It says spread out. Like an expanse. I know that some did translate Mahdan as Carpet. Thta is without considering the Quranic Arabic, it means bed or resting place, With streets. Water from the sky.
6. Earth or heaven?
The Quran does not give a chronological order of creation in the verses you are referring to. They are separate events.
7. The sun travels.
It does. What do you take as wrong in this if you dont mind me asking?
Generally we hear a lot of people say "Your scholar", "This translation" etc. But you have intellect, so just try and make an analysis by yourself. Logically.
Cheers.