Not drawing intersecting areas: not appropriate for anything IMO (even with eggs/om you may want to build something that is in range of more than 1 creep source), except repeaters *if* you additionally draw a plane exactly between the 2 repeaters, so you could see which is closer.
*Technically* it may be possible, tho I don't know yet. If it is, it's probably too inefficient on q3. I'm guessing it would be a piece of cake with full access to stencil and depth buffers.
I've thought about additionally drawing on all map geometry (not just at edges) inside any power area, and it should be easy, but it's not implemented yet. However that would also mean drawing on all players & buildables in power areas and that may look weird...
About precision: we already did get around the .md3 precision problem (tho we noticed the problem with cones) by using models with radius 100 that are scaled by range/100, so yes, that definitely works.
Another possible cause for the mismatch on Brindus is having the sphere centered above the center of the RC range.
The view is not nearly as obstructed when only displaying the lines on walls.