First let me say thank you for the wonderful software. As it sits, it does what I need and it would be fine that way. If you did want to improve it, I have a couple suggestions. I have been using PFranks Renamer in windows for years, so I've gotten lazy with certain things. The biggest difference would be the drop-down with numerous built-in commands ready to go for all but the most demanding renaming functions. Stack and reorder a few of these and you're on your way.
Beyond that, I find myself hunting down exact commands in the order list as the all keep the original name when you dragged it down. Being able to name these and have the window expand to accommodate the custom names would be a big help. The other thing that slows me down is the per character regex checker that takes me to the error screen on every typed character when I have existing files in the list. I bypass this by writing the regex with the regex box un-ticked, but when I forget, it's a pain. Maybe there's an option I haven't located yet to turn off the autocheck yet, but I'm fine with having it wait till I hit the preview button when I'm in the rename window, but automatic results in the file chooser window.
1 - Some easily selectable built-in commands for the most often renaming actions. (A dropdown in the rules window, with room for a few custom rule sets / configs)
2 - Ability to rename the rules.
3. Regex error checking only after hitting Preview button
4. Handy Regex reference drop-down or window without launching a browser. (Quick Help?)
5. Shortcut (F2) to manually edit list entries, and remember entries when more files are added. Only cleared by hitting Preview again.
As I said before, this will get what I need done as it is and am extremely thankful for your work. I hope you consider these suggestion for what they are to help make the program more accessible for forgetful people like myself.