Ah crap, I still don't get it :S

So you say a NURBS patch is limited to 4 sides... well so is a NURBS patch, right?
I don't quite understand this bezier limitation... can't you have any number of patches in a grid with both NURBS and bezier?

You usually stick beziers together in groups of... 4? or 2? (maybe just 1?) Representing a cross-section in a grid. each of these consist of 3x4 points (one for corner position, and 2 for defining curvature), these are treated as 1 point with 4 "arms" in for example 3ds max.

3ds max usually locks the arms 2 by 2, Like this:
The normal represented by one arm is continued over in the superjacent arm so if you draw a line between the 2 points it will go through the middle "position" point.
So you're sure you'll have at least 2G (?) continuity.
So you might in reality have several points, but in practice you only have 1 point with 2 "vectors" (1 vector defining length from and angle/normal to middle point, for each two superjacent points).
I don't get why these points couldn't be interpolated in a sweep just like the b-spline points in a NURBS swept surface...