As much thought as you have out into this, it all falls apart on one single assumption you made:
Given that this is a boost to earnings in Open rather than a nerf to earnings in the other game modes, the only possible objection to this (and the above suggestion in point 1) that a player might have is because they want to be able to affect other players without running the risk of being opposed. In my view, this isn’t a legitimate objection.
And that's entirely wrong.
While there are who choose to not play in Open because of what you described here, I know a lot of players who actually rather enjoy the "ghost town" you described.
They don't really want to interact with other players, except a few friends they made. For whatever reason they may have for this.
Apart from that, I know many players who are interested in the BGS, but not in pvp. Not in the slightest. And forcing them into Open due to actions having a much bigger effect is a not a good idea. It's basically taking something away from them and they will not go and provide the pvp interested players the content they're looking for.
Rather they will stop doing it, or try finding a place where they keep being undisturbed.
Same thing goes for earnings, that's a very bad idea. Elite wasn't intended in this way, which is also why FDev mentioned they have no plans regarding this.
Blaze your own trail, that includes of having the choice to engage with others, or not. It shouldn't have come with restrictions if you choose no.
Look at World of Wacraft for example, the rewards are not higher for those people who choose to play with pvp enabled, and it works perfectly fine.
Now, to the crime and punishment part:
I've already wrote to you on Distant Radio discord about what EvE online did with the security levels and what you proposed does take a similar-ish approach.
Here's what I would do:
High Security Systems: ATR responding immediatly to attacking a clean CMDR who is not a war target. + Massive loss of reputation with the controlling faction.
Medium Security Systems: ATR responding at continued offenses (Notoriety 5+) + big loss of reputation with controlling faction.
Low Security Systems: Police system like it currently is + some loss of reputation with controlling faction.
Anarchy: Same as it is today.
On that note, ATR does need some buffs because there are ways to avoid them still: "Grombomb" effect on main weapons and way faster engines.
Additionally, stations controlled by factions who are hostile to you due to low reputation must open fire when getting near (not sure if they already do).
As fleetcarriers can provide safe docking ports for criminals: Introduce a fee for parking carriers in systems, with the amount depending on the security level (anarchy being for free).
Changing security levels being part of BGS makes players have an interest to work for making their space safer.