If it's the page I linked to above that you're talking about, it isn't miy site - simply a site for a client of mine, and I will pass your comments onto him.
Where do I find Timewarp etc, and how do I apply them to my video?
Shall I still output in .flv (web, small)?
You may also have to edit the export settings.
When you export to flv with the preconfiguration "web small" you shall dig in it and adjust the data rate (lower it until you get the quality you want).
Sadly, encoding isn't a skill that have a long curve of learning, and relying on pressets is just the first step (and encoding much depends on what is in the frame, so it's a science by itself as soon as you want more control on your outputs). Also, AE is a compositing system, not an encoding software, so if you have the Production Premium, Master Coolection or Premiere, you should definitly want to export your project from the Adobe Media Encoder.
One of the most important step in downsizing the size of your video while keeping quality is to do "dual pass" encoding, and AE can't do that.
The great thing is that you can import an AE composition right inside AME, so you don't need to do a temp encoding.