When uploading a picture and than inserting it into the post, let the USER decide, whether to link to its source or not (unlike 2.9, where it is linked automatically). The same thing with the size proposal. Don’t let WP decide, whether to automatically select a different size of the picture from the original one.
Also allow somehow to “protect” some registered nicknames (like the admin’s nickname) from other users in the comments. So if Jerry is the admin, no one else on that blog could be named Jerry.
