Sounds good TR!
Maybe one way to find good candidates are any verse where the translators have bracketed interpolations based on tafsir or wishful thinking, or where the translators disagree with each other on what it means. The book the folks here translated has some examples of obscure verses like 20:96 and 38:84 in section 4.6 & 4.7 (though playing Allah's advocate, 3:7 seems to say only Allah knows the hidden meaning of some verses - very cunning!).
http://councilofexmuslims.com/docs/My_Ordeal_With_The_Quran/My_Ordeal_With_The_Quran-en-latest.pdfYour example 18:86 is a key one as it's so controversial. Some translators like to add various interpolations such as "he found it [as if] it set".
I'll hazard an attempt for 18:86 (I almost wish I'd never seen this verse!) and hopefully Hassan or someone can correct / improve it? It might be overcomplicated for the purpose of your website though, so I dunno if it's better to just include one of these suggested changes for each verse (assuming any of them are acceptable) and remove some of the detail.
It's hard to improve the first part of the verse without saying "if it really means x, a better solution would have been to say this; if it really means y, ...", so I'll just use the most popular interpretation (that it means he went to the west and east).
[I can't paste the underlining and bold from the transliteration but that would need to be added if included on your site]
Verse: 18:86 "Till, when he reached the setting-place of the sun, he found it going down into a muddy spring..."
حَتَّى إِذَا بَلَغَ مَغْرِبَ الشَّمْسِ وَجَدَهَا تَغْرُبُ فِي عَيْنٍ حَمِئَةٍ
Hatta itha balagha maghriba alshshamsi wajadaha taghrubu fee AAaynin hami-atin
Problem: This can be misunderstood to mean the Earth is flat, because it implies a single point at which the sun sets, and that it sets into a muddy spring.
Solution: Supposing, for example, that it is actually describing a journey to the west, and a view of sunset looking out to sea. Any or all of the following would have made that meaning clearer:
1.Remove alshshamsi ("of the sun") since al maghriba ("the setting place") on its own often means the west elsewhere in the Qur'an and replace wajadaha ("he found it") with wajada alshshamsa ("he found the sun").
2.Insert kaanna ("as if") before (or after?) taghrubu ("it set"); or
3.Replace fee ("in") with waraa ("behind")
New verse: 18:86 "Till, when he reached the west, he found the sun going down behind a muddy spring..."
حَتَّى إِذَا بَلَغَ الْمَغْرِبَ وَجَدَ الشَّمْسَ تَغْرُبُ وَرَاء عَيْنٍ حَمِئَةٍ
Hatta itha balagha almaghriba wajada alshshamsa taghrubu waraa AAaynin hami-atin
Here's an attempt for 18:90 too:
Verse: 18:90"Till, when he reached the rising-place of the sun, he found it rising on a people for whom We had appointed no shelter therefrom."
حَتَّى إِذَا بَلَغَ مَطْلِعَ الشَّمْسِ وَجَدَهَا تَطْلُعُ عَلَى قَوْمٍ لَّمْ نَجْعَل لَّهُم مِّن دُونِهَا سِتْرًا
Hatta itha balagha matliAAa alshshamsi wajadaha tatluAAu AAala qawmin lam najAAal lahum min dooniha sitran
Problem: See problem with 18:86 above. If, for example, it means he reached the east in 18:90, Allah could have made it much clearer. In particular, everywhere else in the Qur'an where west is mentioned, mashriq is used to mean the east, and al matliAA ("the rising place") is not used anywhere else in the Qur'an to mean east (and in the sunni hadith it is only used with the literal meanings).
Solution:
1. Replace matliAAa with al mashriqa. Also replace tatluAAu ("it rising") with tashruqu (which also means "it rising") to maintain aesthetics since just as matliAA is derived from the former verb, mashriq is derived from the latter.
2. Remove alshshamsi ("of the sun") since al mashriqa on its own often means the east and replace wajadaha ("he found it") with wajada alshshamsa ("he found the sun").
New verse: "Till, when he reached the east, he found the sun rising on a people for whom We had appointed no shelter therefrom."
حَتَّى إِذَا بَلَغَ الْمَشْرِقَ وَجَدَ تَـشْـرُقُ عَلَى قَوْمٍ لَّمْ نَجْعَل لَّهُم مِّن دُونِهَا سِتْرًا
Hatta itha balagha almashriqa wajada alshshamsa tashruqu AAala qawmin lam najAAal lahum min dooniha sitran
Hopefully someone will confirm / correct / improve the above. There must be even clearer, yet suitably poetic ways of completely rewording these verses so it didn't reinforce flat earth, geocentric beliefs and make it look man-made today, but at least these minor changes would have helped.