I think I'd lean that way too, because I like the idea of the locals controlling the system space (Imperial vessels can come and go without challenge, but the space belongs to the system - except in systems that are non-starfaring).
The Imperial presence in the port might be "Here's the Imperial laws we expect you to enforce. We'll station some SPA inspectors that will accompany your customs inspectors on a random basis. If certain things are found, those inspectors and/or the Navy will be called."
That would let ports be local, but have Imperial Law respected and enough scrutiny to keep the locals mostly honest. If the SPA inspectors were denied access to an inspection flight or found evidence of flights being routed around Imperial inspection regimes, they would notify the local Imperial political/legal authorities and maybe the local Navy. The threat of having the Imperium drop hard into a system would be the guarantor in most cases of the locals staying largely above board.
This level of oversight sees Imperial Law done but the footprint of the Imperium is much less heavy and less front-and-center which would make it more palatable to any planetary system. The reality of the Imperial Navy and other agencies would help ensure this 'soft power' approach still gets the job done.
I'd actually think that blasting out comms in an omnidirectional basis is not that useful. It clogs up frequencies and burns a LOT of power (omnidirectional broadcast comms is brutal over larger coverage areas). I'd think instead that you'd have a system as follows:
a) You have a beacon that advertises in a short omnidirectional manner indicating its location and the particulars of point-to-point laser comms. Said beacon also supports fairly decent passive sensors to identify ship arrivals in the area.
b) Ships would use a directional laser to link up, get data at a higher data rate than radio (useful for data downloads) and also much more sippy on power consumption. The beacon would support a number of emitters in order to support traffic but there could be times you have to wait a few minutes to have access. The use of point-to-point also makes the comms more private.
c) You'd pull all the NOTAMS and TFRs and so on plus any other key local laws or warnings from the local government, probably customs info and immigration info too.
You would have a powerful directional radio system for the few ships that might have no laser comms or they have been damaged. Even a directional radio is more energy efficient than an omnidirectional radio, by a long piece.
In high tech beacons, you might have meson beacons for instant comms.
That's how I think I'd imagine things working.