Hi Ellen,
1: You can see directions here: http://docs.tubepres...-php/index.html
on how to install TubePress into a PHP site. It is not quite as easy as a wordpress site (because WordPress you simply place the [tubepress] shortcode where you want your gallery to display. If you feel the PHP integration is beyond your experience level, you should take a look at TubePress Express (http://express.tubepress.com) as that is usable on any website and only requires the placement of a single line of code for your gallery to display. We even provide you exactly what that code should be.
2: You can only determine the order of thumbnails if using a YouTube Playlist, at then it will display in the order of your playlist.
3: Free and Pro users are offered support via this forum. Pro users have priority (ie their questions are answered first, within 24hrs Monday - Friday) We also offer extended levels of support, with the top level including live telephone support. If you are interested in those, please let me know and I will provide you with more information.
Thanks!