there much wrong Aliases, how them to delete?

fluffy ist not the same like fluffy_(artist)
solo isn't 1girl, solo can also 1_boy or 1_herm ... solo mean a single character

Contact Kielan. As an admin, he is the only one who could do what.

xbooru.com/index.php?page...=profile&uname=Kielan

The better question is: Why have they been approved at all?

There's are couple that might be wrong, not much, much would be dozens, there ain't, we cannot change them either, it's why we don't approve many.