Where is it safe? Can I avoid PvP?

Hubs are safe, including Greylock (a contested hub with both factions present). No breach is fully safe.

• Hubs allow no fighting unless both pilots accept a duel, and duels are to the death.
• A faction hub admits only its own faction. Greylock is open to both.
• Each faction has lower-tier breaches the enemy faction cannot enter. Even there, allies can still shoot you; it just costs them Merits.
• Breaches hold other players as well as NPCs.
• The Gallows and Cloud Wake are unrestricted war zones (no build-rating limit).
• Other dungeon maps require a build rating within their range to enter. Cargo counts toward it at 25%.