My English level is average. I can write fluently and my vocabulary is not too limited.
With the thought in mind that the end result must be perfect, is it better for me to write my long text (100 pages) in English and then get copyedited by a native English speaker, or write in French (my native language) and then get translated by a professional?
I'm concerned about the quality of translations. Long texts (such as reports, offers, books, etc.) that have been translated into French from English are usually done very poorly.
I'm also concerned by my inability to use English correctly, especially with expressions and with typical ways of constructing sentences in particular contexts.