Hmm, if it isn't debatable, than why are you debating it?
OK, just kiddin' there! Put down the plasma launcher!
I think if you include the "outside the hull" idea for WP components, you need to remember to boost the cost of the internal components to reflect that.
IOW, if you are supposed to be relying on the civilian power grid to run your WP cannon, you would need to make sure that grid is properly hardened, brown-out control is provided for vital civilian services, and so forth. Plus, of course, you'd have to put in all the cabling and support facilities to provide the access channel. The costs for all of this have to be paid for somehow!
You also need to find a rational of how these WPs would be able to function the same way when dropped on a brand new colony which hasn't even built its first facility.
This isn't to say you can't do all this . . . only that your "half-mounts" for WPs with their external support networks should cost quite a bit more than the equivalent base mountings. The inefficency inherent in such a set up, as well as the increased complexity of the engineering demands, would be quite costly to overcome.
In any case though, I don't think WP ranges need to be changed at all. Transports need to close to drop their troops and WPs, unless technologically outmatched (and upgrading units is
definitely an issue I'd love to see addressed!), do a good enough job of keeping them at bay.
One thing that has rather bothered me about WPs on worlds with atmospheres is the fact their beam and kinetic weapons pierce the atmosphere without penalty. They shouldn't be able to deliver the same punch with the same weapon as a ship who doesn't have to cut through an atmosphere to hit its target. And the same should go for attacking ground-side targets from above, of course.
I think there should be a penalty assessed for beam weapons used by and against ground targets on worlds with an atmosphere. Missiles should be able to avoid this penalty and that would make an interesting situation when you're faced with a combined defense of satellites and WPs. The missiles would be best against the WPs but useless against the satellites.