Are there any problems in building a door from solid plywood? Perhaps the frame type construction is popular due to lower weight (due to a thinner panel or hollow core)? Since my doors will be small, this shouldn't be an issue. The biggest issue I see is making a perfectly square cutout to accept the glass, and blending the edges of the hole in with the surrounding birch veneer (I'd like the edges to be rounded). Is a router even the best tool to use for this, or would a jigsaw and a straightedge work well enough?
Also, how deeply can I route the hole, in terms of distance to the plywood's outside surface, without risking damage to the plywood (from splintering, etc.)?
Finally, if I use a rounded edge along the perimeter of the hole (when viewed from the front of the door), can veneer edge tape be used to cover up the exposed plywood grain? I know edge banding can be curved lengthwise, but is it as flexible when curved along it's length (e.g. to cover the length of quarter round moulding)?
If not, I can cut the hole with square edges and glue on strips of quarter round moulding to the inside edge of the hole.