Looks like I got this extension "working" after implementing the corrections found in the comments.
However, it seems to be stuck with the default "poster".
<?php $this->widget('ext.smp.StrobeMediaPlayback',array( 'src'=>$model->url, 'width'=>'400', 'height'=>'300', 'allowFullScreen'=>'true', 'poster'=>'$model->poster', 'endOfVideoOverlay'=>'$model->poster', ));?>
That doesn't seem to change the "poster" attribute, even after deleting the contents of assets. However, I go into protected/extensions/smp/StrobeMediaPlayback.php and edit the poster attribute directly, it does work.
Also, I see no "fullscreen" button on the player regardless of the configuration.