1. You can't add a video before a DVD menu in Premiere Elements. You will need to use a third-party disc authoring program like DVD Architect Studio.
2. Adding text should not make the video choppy. However, it is possible that you'll need to render your timeline (press Enter) in order to get a smooth playback of your timeline while you're editing your movie.
3. Once you load a video to YouTube, YouTube re-encodes it to their own format. This can take up to an hour. If you're still need seeing your movie after an hour or so, you need to find out what's going on at Youtube's end.
4. The best format for creating video for YouTube depends on which version of the program you're using. This article explains how to do it with version 10. http://forums.adobe.com/thread/623549?tstart=0
Meantime, if you'd like to know lots more about the basics of this program, you can check out my books on Amazon or my free 8 part Basic Training tutorial series at Premiere Elements support site Muvipix.com.
Here are the tutorials for versions 11 and 12.
And these "Intro to" tutorials are the 8 part Basic Training for previous versions, including version 10.
Steve ... awesome help ... rendering solved my perceived choppyness issue ... file format was perfect for YouTube ... thanks again ... I've got a few more to sort out ... new forum coming ... thanks again ... Woody