I wasn't quite sure where to ask this, but I thought it might fit in here best. I figured out that my users are generally struggeling with the wordpress backend as they just want to do a single thing, posting a custom post type, which is a photoblog. To increase the happyness and make them post more stuff I'm looking forward to make the process as simple and convenient as possible. My idea is to create a site within the wordpress backend that displays all posts of the current logged-in user in a simple list with a thumb of the linked picture. The user should be able to select either a folder or files from his disk and upload them without the dialogs of the wordpress media library. Simple select and upload in background. As I'm talking about a photoblog, each picture represents a picture, so I want to cycle through each uploaded, read the exif, fill some fields and then post it.
After this long description, my question: What would be the "best" choice to achieve this? I was first thinking of a separate php site using xml-rpc, accessable through the wordpress backend. This gives me the most flexibility but I have some issues with security, as I need to obtain the valid credentials (username & pass) which I don't know right now once the user is logged in. Another option would be to create a wordpress plugin, but I couldn't find hints how to interact with the media library properly. As I'm fairly new to wordpress this might also take more time to get into the mechanics of wordpress.
I'm more than happy for any kind of hint or advice what to do or which solution might be better.