Youtube embedded player can be adjusted a lot using the parameters available here https://developers.google.com/youtube/player_parameters. Some parameters are available on both HTML5 and flash players and some are not.
Check out https://developers.google.com/youtube/youtube_player_demo, for all availabel configuration and play with it.
For example you can hide the controllers in embedded video, by setting parameter controls to 0
src="http://www.youtube.com/embed/p09QlQQazo0?controls=0"
width="640" height="360">
Default video quality can be set using vq.
allowfullscreen>
Youtube allows you to have its logo to be modest, by setting modestbranding to 1.
We can also set all of these values together
style="border: 5px solid #cccccc; overflow: hidden;" width="640" height="360"
frameborder="0" allowfullscreen>