IMO the biggest #1 problem with open is that there's no reason to even play in open unless you are looking for a fight. If frontier can ever fix that problem, that'd be a huge step forward. But right now I admit I have no idea on how to tackle this issue, without screwing solo players.
The problem #2 is that even if you are looking for a fight... its a big unorganized mess. There is no system to encourage PVPers to fight each others. And there is no system to adequately protect traders/PVEers.
I'll tell you something ; I played EVE and was never "ganked" or "killed" when I didn't want to. EVE is organized. There are high security sectors, med / low and null sec. In high / med sec, you are fairly safe. The security service ships react FAST to any criminal activity, and they will quickly dispatch anything that remotely attempt to harm you. They are slower to respond (and also weaker) in low sec. Finally there is nothing to protect you in null sec.
I spent most of my time in high/med. But when I wanted to have some fun I ventured into low/null. And got killed. And it was fun.
At the same time, EVE also has tons of systems that makes pvp "meaningful". Its not only players ganking random players. They are fighting for something, usually. Either ressources, control of a territory, player owned station, etc. Thats why PVPers are actually BUSY fighting other PVPers, and NOT chasing traders in boredom.
I tell you, the way to fix open is something like this. Make it organized. The galaxy is HUGE, there is space for everyone. Create "safe"ish zones for PVE players. Create combat zones (with meaningful PVP content) for pvpers. You cant just dump both kind of players into an empty universe and hope it'll work out.