Word choices from English to Arabic
I noticed how lazy I am with this exercise where you proceed by elimination. The Arabic words offered often makes it too easy to discriminate between them. Maybe at first, it is not so bad, but as you progress, it becomes too cumbersome. I also wish the lessons made more use of words used in previous ones so you are reminded of vocabulary you should know by now. I hope Duolingo can fix these two issues and raise the bar a bit more. That way, these exercises would bring on a better memory effort on the student's part.
I admire your effort and ingenuity! I do write down the words by hand (albeit awkwardly) on a notebook and even make whole lines of اَلْشَّمْس اَلْشَّمْس اَلْشَّمْس اَلْشَّمْس اَلْشَّمْس اَلْشَّمْس and that helps a little. Your system is labor intensive too, but a better idea than mine.
I think writing by hand is a still more effectiv way of learning. But I am too lazy to do that. I must admit, when using the keyboard I let out the diacritics. Duolingo accepts it like that too. Interestingly the words written without all the diacritics suddenly appear less complicated and intimidating.
Actually, FYI, a lot of natives and fluent speakers of Arabic leave out the diacritics all the time when using a keyboard. For example on the phone to text someone or search something, write notes, etc. It's because after you've become used to reading a lot of words and different sentences, it becomes easier for you to guess the right way to pronounce a word/sentence. Sometimes you still need them on certain words but even then, with practice you'll be reading everything without diacritics. And as you said, the writing looks A LOT simpler when you leave them out. It reminds me of read or read (past tense) in English (and even red sounding the same). This is kinda like that, when you can use context clues after a lot of practice and time reading.