Outside is just PvE, yes. I personally don't like the PvE part, it's fun with buddies, but the real treasure of the game is the dark zone.
I would say it's equal levels skill and stats. For example I can't really kill someone on level 30 when I'm on level 15, but I had no problem killing someone on level 19, because I used my abilities and the cover better.
I can only recommend this game, it's pretty much DayZ without zombies and with the trouble of bandits handled correctly. The interface is also not cluttered at all, it's very easy to see what's what.