I want to talk about manga translations done by amateur translators.
Many manga (hentai or not) are very poorly translated from Japanese to English, because of lack of knowledge in Japanese or experience. Or maybe they are just trolls who do a bad job on purpose.
I recently came across a non-H manga translated to English, and is was full of mistakes. The problem is that the people who read them have no way to tell if the translation are accurate or not.
This is disappointing but I have no real way to fix this problem. People reading them are really missing out. I try to provide help on E-Hentai forums but only a few actually come for help.
And before you say that I'm a bad translator too, no I AM Japanese so I know what I'm doing. I have a JLPT1 (Japanese Language Proficiency Level 1). I wish more Japanese people would get involved in the translation scene but they lack the English skills required.