I read somewhere that you do not lose security status for actions that take place in Null Sec ( Systems with security level of Zero or below ) So given that I what I read is correct are NPC corporation standings affected by actions that took place in Null ?
Actions in null do not hurt security status but can negatively impact faction and corp standing.
Security status is lost only in PVP / player combat, in high-sec, because high-sec has extra combat rules and Concord. If you declare war, and kill war targets, then you don’t lose sec status even in high-sec. Otherwise, null is free for all, so no sec status loss there for piracy or PVP.
Security status is gained by killing NPC rats or turning in tags, and these actions aren’t affected by high-sec, low-sec, or null, it’s just a matter of where the NPC rats are, and where the tag agents are.
NPC corporation standings are completely separate from security status. You lose standings by killing NPCs that belong to the various corporations (yes, the various pirates - Guristas, Angels, etc. - are organized in corporations too, and you can gain positive standings with them, and access their LP stores and get the pirate ships that you see on the market). And you gain standings by doing missions for agents or participating in FW.
The corporations aren’t linked - you can gain all the way to +10 with any number of corps. The Empires (Amarr, Gallente, Caldari, Minmatar, Guristas, Sanshas, Angels, Mordus, etc.) ARE linked, if you get cozy with Amarr you also gain Caldari standings, and you lose Minmatar and Gallente, and various pirate standings. The Concord faction is completely neutral to everyone and isn’t affected by missions.
Yes they are, mostly by PvE as described above. But you also lose standing if you kill/pod a player char within a NPC corporation, with said corp. So it comes for example, that I have -9 standing with my own noob corp.
This is not relevant unless you want to mission for this corp. There are two exceptions, Brutor Tribe runs the market in Hek, so if you want to trade there, you should refrain from podding players in this corp. Also some of the mining corps work with standing in regards to their NPC miners/haulers (I don’t remember which ones).
Security status is also lost for engaging non legal targets in low sec, corporation standings affect your agent access, market trading and reprocessing I think .