I have a simple ActionScript Class that handle rectangular “cards” with various options, including rounded corners, backgrounds and borders. Even has a simple highlight animation. You can animate all the properties using Greensock TweenLite classes.
You can view an example here:
https://casparcgforum.org/t/problem-with-blend-modes-in-flash-templates/678/6?u=rrebuffo
I will post it in a moment.
You could use that or just view it as an example.