Be very careful deleting or erasing anything in the Android folder. Some of those "files" may be "shadow" versions of "real" files, like Photos or Music or docs. They are in fact kind of pointers to your other files so that Android apps can find and use them. But while they appear to be duplicates, if you erase them, they will also be erased in their equivalent BB folders. So you might wind up deleting photos or docs that you want to keep.
I did a security wipe and boy does it perform better
Ran into the bb10-0015 error but just installed new version of BlackBerry Link and restored software