It looks like you answered your questions already, but I’ll chime in to see if I can be any help.
First I would suggest using the “Link to .css file” whenever possible. It looks to me like this is the way of the future. You never know with the web, but I don’t see the big players supporting @font-face as well. The spec and examples of @font-face are scattered, sparse and harder to follow. I did find one decent one here, @font-face rule (Internet Explorer).
Assumption 1: This is absolutely correct. You need to directly reference a font definition. From the above spec: ‘Possible fontFormat values are “woff”, “truetype”, “opentype”, and “embedded-opentype”.’
Assumption 2: I am a little confused on this one after you follow up, so I will just say this: You can choose the Web Font directly on the Widget. In the original example “MyFirstFont” is chosen directly on the Widget, but it does have to be typed into the combo box because the OS doesn’t know about that font (we could try to add those in, in the future). You could also use a Font Mapping to map something like Arial to MyFirstFont an then you could select Arial.
Font Mappings and Web Fonts are two completely separate concepts that are very powerful together. We certainly intended them to be used together in many situations, but they by no means must be used together. I wish we had some better documentation explaining each of them in detail alone as well (we’ll look into that).