I am not exactly sure what you are trying to accomplish. You have probably found a good method. You can set objects to "Send to Front" and they don't pass as much light through them as "Send to Back" but they do still pass some light. I tend to raise walls of orbits up a couple of mm so shadow maps pass under them. Then drop the top of the wall the same distance so it looks intentional. I have never used the new style of models that TerryRed uses but I vaguely remember that he said they don't pass light (I might be wrong).
The Glow Radius adjustment in the FP editor only goes down to 20 but you can go down to 0 using BAM script although I probably wouldn't go that low. Then you can set brightness using BAM script higher than the default of 1. If I remember correctly, the glow is what passes through objects and brightness less so. You can look the small red lights on each of the flying saucers on "Attack From Mars" that I just posted. I actually set glow radius to 0 and brightness was set pretty high. I seem to remember having problems with light passing through the saucers.
I tend to use Slamt1lt's method for bulbs under the plastics. On "Attack From Mars", each bulb under the plastics is actually a set of 2 bulbs. One is rendered, "Sent to Back", locked and set on the playfield. The other bulb is what I call a "Glow Bulb" and is unrendered, "Sent to Front", unlocked and set higher (about 20 mm). I overlap the 2 bulbs a little bit in the editor so I can verify the unlocked bulb appears on top the locked bulb to make sure the Send to Front/Back is set right. I set shadow maps to the rendered bulbs. This method might work with your low glow on the rendered bulbs and high glow on the unrendered bulbs. It also makes it so the glow doesn't move when you move the camera.
It looks like you may end up adding BAM script to every bulb, light insert and flasher on the table like I do (well there are a few I leave unscripted but not many).
Hopefully this helps.
