Through my own testing I can easily say this: We need a sector size increase. How big exactly? I'm still not sure. I'm seeing what happens between the 4 and 8 km sectors. The sweet spot might be somewhere in the 5 or 6 km range. This will require a corresponding increase in speed cap as well. Otherwise we just broke the server for half the users by making their go-to ships too slow to traverse sectors now twice the size.
Treating NASS running SM like a production Eve server is just going to result in disappointment. Squad battles using ships roughly 60x60x30, with a single capship keeping its distance from any other capship or station, is within the capacity of the server. But only just. Adjusting sector sizes to suit this style over capship slug fests is the most sustainable option. Otherwise we end up with huge sectors and huge lag and no one willing to put up with either.
Remember, NASS is not meant to be a fleet action PvP server. The universe is shared between PvE PvP and now Build users. Squad skirmishes of smaller ships, and I mean tiny by comparison to the vessels last used, are more in tune with NASS' hardware capabilities. Only a dedicated Battle server should be used for PvP fleet actions. Considering the expense involved it is unlikely NASS will get a dedicated Battle server.
Server restarts are a big maybe. They don't appear to have an effect server side worth disrupting everyone. It may well be just your client. There's a chance it is bogged down and desyncing you. That WOULD show up as being server side lag. If multiple folks are experiencing it but not ALL then you're all likely having sync issues. This can happen when positional data a screwy client generates for itself clashes with packets that the server sanity checked. The only real fix is all affected clients relog.