I have no idea about the first error, you should ask in editor help zone. And post the full trriger of these actions. Oh and how exactly the game crush? This may be caused by leaks if you didn't fix them, there's a tutorial how to fix those.
That's not hard with the +1. See, I just don't remember how exactly thosde are called (like "Last unit picked" or "Matching condition", one of those). So one of those things should be something like ['Something" 1]+["Something (probably Integer, by the way)" 2]. So see, the + may be changed to -, * or / if you want, and as first integer or whatever you make the player kills, and second integer or whatever is just 1, which isn't hard to choose.
Well I'm bad with explaining but this should help you, I hope. Otherwise you can ask in WE help zone.