I turned off just the error checking for Required Action Fields, which fixes it, thanks. Hope that doesn't cause other issues, I think I'm good enough at filling in the required fields on the actions I use.
The not deleting bug happens mostly when you click in a field to enter text, and then try deleting the action or any other actions. If you press enter to accept the typed changes they should delete just fine. But it doesn't always work and the only way I've found to fix it, is to do the state deselect/reselect thing.
Just add a Send Event By Name action, click in the Send Event text field (no need to type anything), then try deleting the action. Happens every time.
Clicking on the action name bar at the top of each action (so you can delete it) should take focus away from the text field, currently it doesn't. That might be enough to fix it.
See my example image. Name bar is blue after being clicked on but text field still has cursor line.