Perhaps this might go well with my proposed SAFETY system. Both of which can work hand-and-hand.

https://docs.google.com/drawings/d/1U6hArz8JY-QD3ZEGYxqXepq2v43ymPmP_-7eaZ9C0ic/edit

The times you propose would be appropriate in EVE, but are too long for DUST. With the number of times Blueberries step in front of my HMG I would be yellow tagged 100% of the time. I think 30 seconds for 10% damage would be more appropriate (5 minutes for 100%). That would be 10 minutes for a kill.

Also, the victim should be able to kill the person they were killed by once without penalty (Kill Rights), but doing so should clear that personGÇÖs penalty flags.

We could also reduce security status for killing friendlies in High and Low Sec. Then if someone kills too many friendlies they start losing access to Salvaging Grounds in the highest security systems (1 & 0.9). Then as their security status drops further they loose access to the 0.8 and 0.7 systems, and then finally the 0.6 & 0.5 systems. When their security status gets low enough people will be able to team kill them without suffering any penalty in Low Sec.

How much of a hit your security status takes from a friendly kill should be proportional to the security status of the system, so friendly kills in High security space would drops your security status much faster than friendly kills in Low Security space.

I'm the player that will be killing other players massively(if it will be profitable) - think for a moment in that perspective, ok.

I think that marking other players with rainbow colors for killing each other in First Person Shooter it's not good idea. Mechanics that works for EVE not necessary will work for Dust/Legion.
In EVE when you find red's on local(low-s/null sec) you can perform a few task in order to prevent 'meeting' them if you think that you have no chance with them. Whatever you do it is time consuming, but you have to spend that time in order to get out of this situation safely. Sometimes you can not simply turn off game, or your computer because they will scan dawn your ship and destroy it.

EVE have open world - Dust not really. In FPS it is always will be 16 vs 16(or x vs x) for another 15 minutes. If Dust/Legion player will join match and see someone colored, he will quickly assess situations and leave without consequences - it will take him five seconds. Sooner or later he will find match that fit his needs perfectly(paradise for carebears with unicorns, mermaids and fluffy clouds). So whats the point of implementing mechanic which will show to players that want to stab each other in the back, and have no problem with it, that this place is for them, and everyone else have to keep looking for they salvaging-paradise?

If you are in empire and you pointing with your Combat Rifle at your friend, you can not pull the trigger - if you spamming trigger button 'CONCORD' security system turns off your weapon for another X sec. or disallow you to use any weapon at your disposal, or shock you with some safe mechanise installed on your weapon so you lose HUD for some time. AoE weapon do not works or can not be activated. In a situation when someone comes to your line of fire, you should be able to continue fire, and guy on line of fire should felt that 'kick' on his back and aim.

I'll try not to sound like the dude who says "this is bad and you should feel bad", but as Snake mentioned this isn't a good idea.

From a lore perspective this wouldn't even work. CONCORD is already losing control of space from, how are they going to police planets too?

From a gameplay perspective, any variation from a binary FF on/off gets too complex and not fun in an FPS. In a more RPG setting it can be more appropriate (think Lineage 2) but not so much in an FPS especially if you start talking about weapon locks, let alone not letting someone play the game. DUST is 16v16 atm, but let's say Legion can go beyond that scale. Think about how not fun this would be if Planetside 2 had something similar, especially during installation sieges. Removing someone from gameplay arbitrarily isn't a fun game mechanic. This is one of the big problems I have with Archeage.

Now if you want to implement the suspect/criminal timers for other gameplay elements to add some risk, that might be interesting. Perhaps something like during salvage missions in low sec, if there are any kills or loots being stolen (how you determine that is another thing) it would show up on the star map and that person has a bounty placed on them. But don't make FF more complicated than it needs to be.

Ah, I thought this was going to apply to all game modes, not just salvaging. Even still I don't think it's necessary to "re-invent the wheel" so to speak.

I do agree that FF off can lead to non-optimal habits and lazy gameplay, but it's not a bad system in itself. Let's say only high sec was FF off, it would appeal to players who don't want to deal with FF and also give a break to people who spend most of their time in low/null. I prefer to play games on the hardest difficulty most of the time, but sometimes I don't. With high sec being FF off I could keep playing Legion and relax rather than having to play another game and relax. As much as you can relax in an FPS.

Also, it wouldn't only just be strange to have particular safety rules in one game in one area of space (why am I discouraged to shoot people in high sec salvage but am not in other salvage modes and also don't even have FF in other high sec modes?), it would remove a person from making money for x amount of time whether by accident or on purpose. I don't know if that's a good idea to deny playtime/income, especially considering that high sec salvage will be of least value, but it will be something. You could be poor/want to grind ISK and play HS salvage without the risk of continuing to stay poor due to others abusing mechanics.

"with FF ON in low sec, and no consequences and tagging of players, what to stop the biggest trolls and jerks to just ruin the experience for everybody?"

Nothing, but what is going to stop those trolls from finding ways to ruin anyone's gameplay regardless of the rules in place? Also nothing. It's going to happen no matter what, in one form or another, so at least have a place, high sec, where you don't have to worry about player killing trolls.

The only real difference in EVE with low and null is low has faction guns in some places. Depending on how well developed the AIs are maybe low sec salvages can have a chance for faction NPCs to drop down, be hostile to everything, and try to take the loot for themselves. This chance could increase with the amount of damage done to players by players, since the empires might be paying more attention to hot spots. I'd rather have something like that than a restriction on gameplay.