So i couldn't pickup any more CZs anymore from that NPC. Is this because no players in the area have activated ( or re-activated? ) certain trigger events making FACTIONS to fight eachother ? And this is totally separate from the upcoming 'PowerPlay 2.0' system, right?
Not necessarily related to player actions - and yes, completely unrelated to Powerplay as is, and probably unrelated to PP 2.0. What you experienced is the "Background Story/Simulation" (or BGS for short) which governs all the things inside that Galaxy that happen, with or without player interaction: faction relations, system states, market prices,, expansion and reduction of a faction's influence area,... . But: just because it can happen without player interaction doesn't mean that players can't influence what's happening here.
One (major!) thread in that respect is still
Turning The Wheel - a player driven event (still ongoing after 4 years) where we tried to sort of force our way inte The Dark Wheel and, ultimately, Raxxla.
In a small (low population) system that hasn't much other player (and especially player group) interest, a single CMDR can push the factions around pretty much as they like. The larger the system becomes, the more random player traffic it gets and the more interested other player (groups) become in that system, the harder it gets. And if other player (groups) are interested in that system (you can usually see on
INARA when one or more factions in that system are labelled as player factions), it's usually considered good manners to at least attempt some diplomatic relations before trying to topple that system's currently leading faction. It's not a good idea to get on the wrong side of, e.g. The Winged Hussars by trying to overtake e.g. 47 Ceti

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With regard to combat zones - you can either look around your local area for other systems with a war ongoing, or you can find a so far quiet little corner of the Galaxy and start a war (or three) by yourself. BTDT in the service of the Black Sky Legion (see Turning The Wheel) more than once

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