I put an action (gotoAndPlay(5)) in the last frame of my movie, and I swear the movie is never reaching the last frame, because I have some text that is supposed to appear briefly on the Stage on just that last frame. It works only if I put the graphics one frame before thegotoAndPlayaction. Why?
This is a critical concept: Frame actions are executed before the on-the-Stage graphics of that frame are displayed. If your action says to go to another frame, it goes to the other frame before it draws graphics on the Stage.
Why does my movie loop (effectively doing agotoAndPlay(1)on the last frame), even though I haven't put any actions in it?
The option to automatically loop is set by default when you test a movie (and when you publish a movie). While testing, you can uncheck the option to loop from the Control menu of the Flash Player (not the Control menu of the Flash authoring program). If you turn this off, you most certainly won't see the movie loop unless you include an action to make it loop. By the way, normally you don't need a stop action at the end of your Timeline; if you simply uncheck the Loop option (when you publish), the movie will automatically stop on the last frame.
Which action do I use to create a commercial video game?
I hope it's obvious that we are taking baby steps first. It's amazing the kind of powerful things you've done this hour. It's going to take a lot more work before you're cranking out video games; although you can create amazing games by using Flash, it takes a lot of work. For now, we're just laying the foundation.