is it even possible to say :"saya menulis nama saya salah" ?
Yes, but since "salah" is an adverb here it should come before the verb.
I wrote that. Duolingo graded it as correct.
It would throw native speakers off, but they should still get what you're trying to say.
That has actually happened to me before. I was at imigration.
I wrongly wrote my name?
It's accepted now. It's what I put first time.
couldn't it also be "saya menulis salah nama saya?"
Saya salah menulis nama saya.. doesnt it transulate to i wrongly wrote my name..?
Would "aku menulis nama saya salah" be incorrect?
Yes, because you're mixing the formal and the informal pronouns.
I wrote saya salah menulis nama aku
The chances of someone saying " I wrongly wrote my name" is pretty damn slim. " I'm sorry, i wrote my name wrong". I cannot write the word Wrong anymore cause it doesn't look right now!