How I work
I believe in asking you what you want (although in many cases I will cockily assume I know what you want). I have occasionally been asked to produce a GIGO translation: this invariably concerned the translation of texts which had already been published. It’s clear that improving on the original is completely inappropriate in such a case, and even unasked, I would reproduce any errors in the source text (barring insignificant typos and the like), while also drawing them to your attention.
In the case of contracts too, I would not presume to improve upon or tidy up the original: in this case, I would point out any doubts or errors to you so that they could be resolved before delivering the final translation.
What about articles for publication? Naturally, I’ll ensure that your text complies with the requisites of the style guide for the journal in question. I might well take additional liberties. I will ruthlessly strike out the vast majority of Latinisms, cold-bloodedly eliminate any tautology or waffle, fearlessly rearrange your ramblings to form a coherent argument, boldly add the occasional point if I think it will strengthen your conclusions.
But I’ll tell you that I’m doing it. You will have the final word. Although naturally, you’ll bow before my superior judgement, because that’s what you’re paying me for, right?