I'm actually really impressed by that 7-Eleven logo --- it looks pretty darn good for a freehand drawing!
One thing that might help with the models is to use Appearance -> "Labeled" for the seconds controller. That way, students wouldn't have to expand the animation to see the value for the slider (even though you made a point to remind them about the animation controls at the beginning of the presentation, I thought they might forget that).
And you can use free-form input to do the unit conversion really easy: just type an equal sign, then something like "5km/hour to meters/second," and evaluate to get an answer.
Overall, though, I found this to be a fun lesson and one that I think your students will enjoy.