Have you tried rendering it to WMV? I have found that if creation and playback is on a Windows machine, Windows Media Player does a much better job of compressing than Quicktime. And you should be able to embed in Open Office.
NTSC and PAL refer more to Standard Definition Broadcast/Tape resolutions and your are correct that they are not standards for web or presentations.
Also when creating for computer screens and live presentations the display settings of the live computer are very important. If you create your video file set at 720 x 540 it is best played back at that size display setting or close to it, say 800×600. In other words, if you were to play this file full screen on a display set at 1920 x 1200 it would look horrible at highest quality rendering.
As to the black stripe through the lettering, this could be what you are thinking and is an interlace problem. Try rendering with de-interlace effect on the text layers. It could also be a hardware issue? Your computer or video card may be struggling to render it. Try to optimize your computer by clearing cache in After Effects before rendering and also using CAPS-LOCK to disable display while rendering.
Lastly, if all else fails it may mean you have to use PowerPoint. You can embed flv files in Microsoft PowerPoint. Surf the web for the tutorial. Its a bit involved but it can be done.
Hope this helps
Kate Caplis
Final Cut Editor & Motion Designer
WhiteHorse BlackCat Studios
http://www.ladiesgeekjournal.com