It seems that whenever I try to approve new members to the community, only the member who "most recently" requested to join the community is given membership, when I will try to approve them all at once. I have no idea how to fix this issue, but as it seems one other community I mod is having this same issue I may have to do a search for a solution, or go to a comm which specifies in answering questions related to problems with particular site features.
So, to anyone who has requested to join the community who was never granted membership, I wanted you to know that your membership was likely not rejected - it just didn't go through, so you can try sending in another request for community membership and I'll see what I can do. If I can't find a solution to this issue, I'll just go ahead and change Sailor Moon Yuri to an "open" community. I had initially decided against that, as the site had a major problem with spam & trolls at the time, but since the site's not nearly that active anymore I'm not as worried.
Hope all of my fellow SM Yuri fans out there are doing great, and I hope any of you who have work you have yet to share or would like to share will do so! :)