It's not a bad idea, although I think that turning it into reality may
prove tricky -- you may well find that the growth of kinds of "hints"
quickly turns explosive when you try to apply it generally.
I agree that this is a potentially serious problem.
For a possible alternative, consider one thought that I've been
playing with for some time (I proposed it here a long time ago) --
keyword-selected objects. In this scheme, you can provide keywords as
an alternative to the URL for an object; if the local system has an
object that fits those keywords, then it just uses that instead of
loading the URL across the Net. As a possible refinement, you can
define "mandatory" keywords (which a prospective object must match)
and "optional" keywords (which may be matched or not, at the discretion
of the browser).
This looks like an interesting scheme to use local objects when approriate. WWWLogical
has quite a different purpose --- the ability to construct a virtual
world consist of logical relationships between objects and letting the
browser decide where to physically place the objects in the 3D scene.
The browser can also create it's own background and structure (such as walls in a room).
Thus the keyword scheme and WWWLogical are completely orthoginal concepts ---
which is usually a good thing.