A general problem I have with cryengine, is that the distance at which you see people depends on graphic settings.
In (and upto VU9), if a person was in radar range, you would see it - it was the radar range that was the "toggle".
In VU10 and cryengine it's the "item quality" settings. With safe mode the range is about 50m or so (to see someone else), with "medium" it's somewhere above 100m. And if you crank it up to medium, if you're on the ground the graphic card will start to render each and every grass straw, you can probably imagine the impact with a lesser graphic card. Practically this means that you need to switch between low/safe mode and mediun if you're going from hunting (=safe move) and going into a fort event or space (=medium).
If you still don't get what I mean, fly up to space station (outside), then switch between safe mode and (very) high, and notice the differnce what you see; other ship and CPSS/FOMA. Or go to oil rig, look down towards where the people usually is and do the same switch.
Personally I would have liked the switch at what distance you see objects to be tied to "viewing distance" rather than item quality, but it appears to be impossible.
But until it's fixed, it means that someone with a better graphic adapter (which you can't scan for ingame but it's not unlikely pk pros have nice graphic cards) have an advantage over someone who has a lesser graphic card, especially in areas with no radar. Someone who's in there for pk:ing can run straight ahead looking in the scope that's attached to a rifle, a miner (equipped with finder) can't to this, both practically (as it would drop the finder) and theoretically (as the pk:er probably just have to look ahead for people as he's running, but the miner is vulnerable from all directions while drilling at a claim or looking on finder which way to run - remember radar is off so you have no claim markers). And if a pk:er can spot the miner from 100m but the miner sees people first when they're at 50m range you could guess what it means.
As for the invulnerability bugs, it should be fixed. (I guess not only could miners use it, a "smart" pk:er could use the same thing to send out a "noob ava" to scout for targets in a safe way - send out the scout, stand next to miner, tell the position out-of-game, and pro pk:er lands next to miner with a huge rocket launcher.)