@Loeffel - all of that you can do in Calibre currently. You can choose single files or an entire folder using the Add button dropdown. You can easily switch between named regexes using the Quick Preferences plugin, as well as toggle the "Swap author firstname and lastname" feature. What there isn't however currently is a way to select specific files out of a folder (however you can instead just drag/drop your selected files from the folder rather than using the Add function).
Does that not cover everything you need?