You ca'nt have Raytraced Reflections with the Image_Map in the PoserSurface Reflection node; becasue there it would drive the reflection %100.   

To have both an Image_Map and Raytracing, you need to put the Image_Map in the Diffuse Color. Then, depending on how much of either you want in your final render, you need to set the Diffuse Value and Reflection Value; by making sure that both do'nt add up to more than "1".

"True reflections" would mean just that, it would mean that everything in the scene(camera position, figures, props...) is tossed into the reflection calculation.  THis is what accurs when you use only Raytracing for reflection, but as I think you understand, this means using a Sky Dome...

So, you use a reflection map for a couple reasons; first that you do'nt really like the color of your scene and how it would effect your shiny metal(Blue skies make green gold,) or that you want to save resources, setting up for..., and then calculating with Raytracing.

Also if you'd read the link I provided on Poser based Sky Domes, you'd certainly have come to understand how the Hi-Res Ball makes for a very poor quailty Sky Dome; with issues regarding Seems, with and without Maps.  And that scaling, alon, is'nt enough.  Once you've scaled a Ball prop, you also need to Reverse Normals,Group Tool) so that the exterior(Infinite) lights will just shine through(as if the ball were'nt there.) and illuminate your figure.   On top of how also plugging the Ball's Image-Map into the Alt. Specular will allow for the Sky Dome to always be visible in your scene preview.