In null, everyone that isn’t an alt of yours is your enemy, either because he’s scamming you or because he’s shooting you. At times, you need to pretend your alts were your enemies, too, eg. when the standing fleet decides to wreck the alt you were using to extract your corps’ ESS with, or the one you were warping on your in-corps toon that cloaky scouted before dropping out of standing fleet and joining your alt’s.
Null is the safest place to mine nevertheless. No NPCs in the higher grade anomalie, no hull integrity tests or mining permit controls, no blopsers, no diamond NPCs, no random travellers picking up miners on dscan and going for them, and even if the miners manage to get wrecked nevertheless, e.g. when the mercoxite cloud burned through the tank that wasn’t tuned in order to maximize profits, they’re SRP-ed.
In WH you know that everyone you don’t explicitly know is hostile, but unlike null you won’t be ganked by your corpmates’ out-of-corps alts, mainly because your corpmates can create enough content by having their alts be in-corps and rolling the static hard enough.
In Low, like in WH land, content is easy to be found, therefore there’s no need to gank your corpmates, either.
In high, even miners are NPSI-ing, but unlike null they’re not PAPI checked to stay in their home system for their activities, so they travel around which preempts there chronic lack of content that null is defined by.
CCP is doing it’s best though. For example, they’re increasing the system securities of the 0.5 secs right now, which will cause their moons to become un-minable.
People who want to shoot miners will shoot them. There’s no need for the miner to be suspect, all that’s needed is void s on enough catties and safety set to red.
The suspect crap is only for antigankers, and AG can’t bother going for miners because they can pad their zkill much better leeching on CONCORD kills in Uedama or Ohide then scrubbing the belts for content on their own.