Here is what I think must be done. This is my opinion only, and I repeat, this only would concern monetary gains.
Firstly, income should be increased across the board, by some small figure around 1% to 5%.
This figure must not be too high, as it might skew balance other way around.
Secondly, Community goals need to get an increase of effort efficiency in Open as well.
Some figure, calculated by related to CG cargo losses in Open, cargo delivered in Open, and the number of PvP destructions in the CG system.
Dealing with pirate blockades is a very entertaining experience, in case of success, of course.
This should be enough. Yet, I want to present some additional possible Open-related features as well, which would add a lot of valuable gameplay.
Arbitrary levels of PvP criminal activity on the GalMap. Is systems where such activity is present, additional income can be added, with variable levels.
In order to not add too much monetary increase here, cooldown might be made rather long. Or, with no income increase at all, this would only serve as a warning on which systems to avoid.
Exploits such system might spawn would only reflect exploits of IRL criminal elements.
Increased profit of rare goods trade.
Pirates know trade routes as well as players, so this activity bears a distinct increased risk in the Open mode.
Can be multiplicative or additive with previous one.
I belive all of this should be implemented as an optional flag in ship's computer to avoid changes in EULA, with parental control if needed. OR it could be enabled from every station, costing (progressive, and with moderately large fee to opt in even at first time) fee to opt in and out, along with cooldowns.
When enabled:
Block functionality should be reduced to chat only.
Menu-log timeout increased.
Loss of P2P connections, as well as severely decreased number of connection between one and other players, should become punishable by loss of any bonuses for current transactions.
Sudden loss of connection will result in the same penalty as above, as well as an additional bounty worth of rebuy of the current ship.
And, essentially, logging to any other game mode while transactions made in Open are in effect will result in the loss of any bonuses as well.