I have been doing some research into what is possible, as far as I can tell
Autoplay
Possible to autostart videos on early versions of IOS http://www.codeblog.co/getting-autoplay-working-on-ios/ although this no longer works on current version (exact version it stopped working I don't know). Behaviour seems to be the same on both the iPad and iPhone?
Playing video in page
On the iPhone videos always pop out to player, its not possible to play in page.
However is possible to play videos in page on the iPad - have tried out the videos on here and they do play inline. http://www.html5rocks.com/en/tutorials/video/basics/
Playing as intro video
May be able to do an enter now button for the site with below code to trigger
<input type="button" value="Play" onClick="document.myMovie.play()">
Could then on iPad make this take the full screen in page in website and use js to detect when the video finishes. Am thinking on iPhone may not be possible to detect when video finishes?
Can anyone clarify what is possible?
As much as I know intro video aren't too popular, this is a requirement for the site.