My suggestion (complaint really) is about the English voice actors. They simply do not speak clearly. More than one of them (particularly Talana and Behrlihn) start each sentence at a reasonable volume and speed but by the end of the sentences they have reduced volume and increased speed to a rapid mutter.
Although from America, I have lived in England and don't have excessive trouble with the accents, if they would simply speak at a reasonable speed and volume. I recall experiencing the same effect with a number of English speakers when I was living there. Its as if they are embarrassed about what they are saying and want to get the sentence over with as soon as possible and speak at a low volume so hopefully no one will pay any attention to what they are saying.
Its bad enough that I have noticed it and been bothered by it and feel compelled to complain about it, because I am constantly fiddling with the volume to try to hear the speech clearly. If it weren't for the subtitles I couldn't understand a good bit of it at all.
