One more thing to add about open play...
Currently, my friends and I play in private group - simply because we have a much better chance of seeing each other than we would in open - with all the networking issues that have been going on during beta. Also, during these testing phases, we have all also played in the open galaxy as well - to see what it's like - and we have found thus far, it's not really much different to private group in terms of getting 'ganked' - it has happened a few times, but not much.
Anyway, I think I'd really like to play in the open galaxy, and I think to want to do that more, I need to gain confidence in the balancing and anti-griefing mechanisms in the game - I am pretty sure FD will tune and tweak these to my satisfaction at some point - so I will be dipping my toes into open, and as time goes on and my confidence in the in-game mechanisms grows, I will do so, more and more, and eventually most of the time. There will still be times where I would play solo or online group - just because I'm feeling a bit anti-social or just want a bit of peace and quiet to go off exploring, or finding new trade routes or whatever.
Having the choice to do this, I think is great, and long term will not dilute the community as some have claimed, but rather help it grow.
That is my opinion.