I think generally most people would like to play in the open but they also do not want to lose credits for being mindlessly ganked. Most ganking is just for the fun of it so I have a idea for a solution.
Create a module that changes the ship's signature to mimic an npc, giving the player a solid square instead of a hollow square on the radar. Gankers would have to scan your ship in order to see that "Cmdr" in the name. That would at least give players who just are trying to get in and out of a system a better chance of survival.
Turning off/spoofing one's IFF shouldn't require a module, but I've always though it should be something we should be capable of. FDev, and much of the community apparently, disagree.
It would also only be a minor inconvenience to gankers and you can already hide your hollow square for much of a supercruise journey by shadowing an NPC sufficiently closely. Of course, once targeted the jig is up.
This or have the system authority react much quicker and deadlier when wanted player is interdicting another.
They can already stretch the bounds of credulity in response time and the most potent extant security forces already have hardware CMDRs cannot match. There is no way to make them fast or powerful enough to provide reliable protection, if they can only respond once an attack has been launch.
Policing cannot be a deterrent as long as consequence are negligible and cannot be a defense unless policing takes initiative gets proactive. Neither of these are likely--the community is profoundly consequence adverse and Frontier is unlikely to treat CMDR on CMDR ganking significantly differently from CMDR on NPC ganking, which most every does at some point. Likewise, NPCs have little persistence, and a new system to enable them to effectively preempt attacks is probably not practical at this point in the game.
Launch your fighter, they hate that.
I won't personally use SLFs while other CMDRs are present, without their permission, due to Frontier never fully addressing the bug they introduced back in 3.4.
That said, this bug is unlikely to crop up over the duration of an interdiction against a trade ship and the SLF is pretty much the only way to have some offsensive capability, outside of ramming, while hardpoints are retracted and spooling one's FSD. The SLF models with a PDT can also be sent after likely dumbfire users to reduce the odds that an FSD reboot munition makes it to target. Of course that presumes there is enough time, but there usually is not.
Depends on what you mean by "paper ships". To make a decent cargo sized trade ship able to stand up to an alpha strike from a well kitted combat ship you'd probably need to put so much defences on it you'd have little room left for cargo.
My shieldless T-9 can survive encounters with most gankers in fully kitted Python Mk-2 frag boats, and it carries more than 700 tons of cargo.
Shields are the problem with defense. Of the ships typically used for cargo, only the Cutter and Anaconda get a more favorable cargo vs. defense ratio from shielding. Essentially every other ship is better off focusing on hull, countermeasures, and mobility, if they want to carry the most cargo with the most protection.
Paper ships = stock ships, shieldless haulers (or small shields) skipping hull day and low resistances... with ship going 590+ can use 500-600mj base shields, with slower ships, need 1500mj base shields and 2k hull at least with MRPs (all with balanced resistances) + submit/HW with fast reboot FSD helps.
I would rather be able to go silent the moment I submit, have multiple PDTs, an ECM, and heatsink launcher...backed by ~5k hull with high resists and an MRP to protect my shielded/armored internals...than token shielding which eats into a hundred more tons of cargo capacity and requires me to try to dodge Grom Bombs in a T-9.
Also - not a solution to ganking - solution to meeting other players while playing in Open ...
There is always Local chat, if one wants to see if someone else is around.