I would try to get at least one of them removed, ideally both. Both of the listing issues revolve around the same thing really, and I don't think you deserve 2 different issues for this one single issue.
As for garden level or basement, yes go with basement if it's the lowest floor and if any part of it is sub ground at all. Although going by the pictures in your listing, it seems to be basement / walk-out basement to me as well.
If it's walk-out basement, then you can mention that as it's definitely better than basement.