The ideal shortcut would be one to make it possible to type away for several frames in a row without using the mouse. Even if said frames have different characters.
That's what I was hoping to do, but you have to select things with your mouse to achieve that: you can't open up certain dialogues with the Firefox keyboard shortcuts, to my knowledge. Correct my if I'm wrong. Therefore, the shortcuts I HAVE been able to make, given the limitations, are (these are all by keyboard):
1. Setting the text color.
2. Setting text voice.
3. Setting text speed (as shown in the tutorial).
4. Merging a bunch of frames.
5. Adding frames by keyboard.
The only solution I can think of is if the mouse always clicked on a specific location, so you had to assure that the textbox you were currently working on was there. For example, the mouse will always select the bottom frame. It's not kosher, as in, it can easily work poorly for various reasons, but it might be the best solution I can think of for now.