I'm not sure if this message belongs here or under Wish List, but I'll start here.
I'm trying to take the approach that a source is a media file and that if I don't have a media file then I don't have a source. I have been taking the approach of building a source under Lists->Source List... and then linking in a media file to the source from there. The linking of the media file to the source includes the Add Media process to add the media file to the Media Gallery.
But because I'm really trying to give primacy to the media file, I have been experimenting with starting instead with Lists->Media gallery... to do the Add Media process, and then tagging the media to a Source. It works pretty well either way, but there is a certain awkwardness in tagging a media file to a source. I wish the process could be improved.
When you first add a new media file and try to tag it to a Source, the Source you are trying to tag it to may not yet exist. But that's ok, and that's more or less the whole point of doing the data entry by starting with the media file. When you first click Tag Media it takes you to the "Tag this image" screen. You select a tag type of Source and the Source box is empty because there is not yet a Source to which the media file has been tagged. So you click on the empty box and it takes you to the Master Source List screen so you can link to an existing source or create the source if it does not already exist. In my case, I create the source and select the newly created source which returns me to the "Tag this image" screen. The process is great thus far - just what you would expect and just what you want. But now I want to edit the tag Ijust entered (or maybe I want to edit the tag a month later). This time the Source box is not empty in the "Tag this image" screen. Rather, it's the name of the source to which the image is tagged. This is totally correct. But when I click the name of the source, it doesn't take me to that source. Rather, it takes me to the beginning of the source list instead and I have to reposition myself to the correct source. This is not good and it is not very user friendly. I wish RM would take you to the source that's tagged instead of to the front of the list.
There are a number of places in RM that work like this - where you enter a list and it takes you to the beginning of the list instead of to the item that you manifestly are already selecting. I don't expect this issue to be addressed in the current version of RM, but I do hope that the developers will be more careful in the RM rewrite about how you are taken into a list when you are already selecting a specific item in the list.