In an attempt to retrieve the value of id, I make the following call:
var is always null, regardless of which ScopedContext enum value I use, so I don't think that's the problem. I would assume that GET request parameters should be in the REQUEST ScopedContext. In any case, what am I doing wrong? Why can't I get the value?
Parameters are not scoped variables. You get parameters from the request instance with getParameter() just like anywhere else. Remember, the whole idea of FrontMan is to help you do the tough stuff more easily -- not to replace the standard ways of doing things with just another proprietary way of doing it.