I would like to be able to create text special effects from scratch and edit existing ones from within CTA.

For instance, it would be nice to be able to replace the chalkboard with a TV monitor, and to be able to adjust the bounding box of the text to fit the TV properly.

Of note, I think these are really props rather than special effects, and so you might just be able to add the ability to add a text box to a prop, and move these things over to props.

Also see, Add timeline for "Text" in text special effects.