Charles, I am coming to your way of thinking as regards the switch. I have put one under the front edge of the table for all three of my table-mounted routers, following the wisdom that one could ďbumpĒ off the power with a hip or knee, in an emergency. But in my disorderly and overpopulated shop, all that has happened is that I have broken off two of the paddles, while moving around (when the routers were not in use). Come to think of it, if things were to go south, it would happen so fast, that I am not sure there would be any real benefit to the front-mounted location.
Regarding the fence itself, I have combined an aluminium angle, the largest standard size available, with two moveable front fences. The L-angle is one piece, with a mouse-hole for the largest bit I am likely to use (horizontal panel raiser).
On the larger table, the split front fences are 32 mmk chipboard (left over from a kitchen counter). They have countersunk bolts, riding in horizontal slots in the L, with star knobs behind the fence.
The smaller table has the same L, but I happened on some extruded aluminium profile, which is rectangular 20mm by 40mm, with two T-slots on each face, and one on each edge. To avoid having to cut a mousehole in such a complicated profile, I opted for two sections, attached to the L with T bolts and Star knobs at the back. But I must say it is overkill, and causes some loss of efficiency with the dust extraction. I am considering splicing the two sections after cutting half a mousehole in each, and then attaching split hardboard fences in front, with countersunk bolts and sliding nuts in the tracks.
One of the benefits of the profile is that it sits squarely on the table top. I found that the L flexed ever so slightly with a tall workpiece. Also, the slightly radiused corners provide an escape for sawdust.