Moreover, VRweb lets you explicitly turn off lighting via a menu option. Yes, it does from version 1.5 on. You can choose between a stipple and a blended transparency method. For details see the online help. Yes, since release 1.2.
Transparent textures work too.
When there are both an inline and an external texture, VRweb will use the inline as thumbnail until loading the external is completed. Splitting polygons into triangles is not necessary. When faces are already convex this will only make files larger without any benefit. In this case you may wish to use triangles or subdivide into smaller polygons anyway. To get consistent results across browsers it may be better to avoid non-convex polygons.