Router table plate Installation/support questions

Hi everyone!

I want to build myself a router table. I got the Bench Dog Pro-Plate and a Triton router.  I've done a lot of searching and collection of information regarding building router tables and I see a lot of ideas.

But when it comes to the question of installing the router plate, I have a few questions:

1) In John White's article - Space-Saving router table - it looks like the plate is supported by the heads of 4 drywall screws.

     - Is it really only 4? None in the middle?

     - Wouldn't the weight of the router bend the plate since it's supported only at the corners?

     - What is done to hold the plate down to the table?

     - It looks like John attached 3/4" thick plywood flanges to hold those drywall screws. So that means the drywall screws extend up from the flanges at least 1/2". Would it be better to fill in those flanges so that only 1/8-1/4" of the drywall screw extends above the flanges? Would that cut down on vibration plus put more threads into the wood?

      - Does the downward pressure/weight of the router compress the plywood fibers around the drywall screws, over time?

2) Cutting a rabbet

     - I have a 3/4" pattern bit (top bearing, 1/4" shank). But that's too long get the bearing to ride on the inside face of the 3/4" plywood template I constructed, and still cut a 1/4" rabbet.

    I looked for a 1/4" shank, 3/4" dia, 1/2" cutting length bit but I don't see it. Can anyone suggest a vendor?

   - what width of rabbet is sufficient to support the plate? 1/4"?

thanks!

Gregg