I think if english is to be used, it shouldn't have to be used right... I mean, unless we can understand Japanese we have no clue what they are saying either... Hell, they could probably be talking about something that makes no sense...
And I don't think Namie is better than BoA at engrish... I think they are at the same level... Namie's can be bad sometimes too...
DAI did 2 songs completely in Engrish I believe... "Summer Days", and "Break Of Dawn"