We’re gonna keep having a lot of confusion and messy threads like this, with more wrong answers than correct ones, until CCP properly documents how these really complex mechanics currently work… CCP, are you listening?
As long as no engagement happens, you may do this and keep ship2 remote sensor boosted with safeties set to green no problem.
The moment this happens, a limited engagement (LE) is created between ship2 and ship3, which would cause anyone assisting any of them to be CONCORDed. Interfering in a limited engagement is now a criminal offence.
The key here is that for ship1 to actually be CONCORDed, it would need to have safety set to red, which wasn’t needed at all to begin with. Ship1 could simply keep remote boosting ship2 with safety set to green until ship2 engages ship3, at which point the safety setting would cause the remote boosting mods in ship1 to automatically deactivate, which is no problem because once ship2 has engaged ship3, such sensor boosting is no longer needed.
That is, the current game mechanics do allow you to do what you want without being CONCORDed, you just have to set safety to green, so the remote sensor boosting automatically deactivates when the LE is created (at which point it’s no longer needed).
Alternatively, both ship1 and ship2 could engage ship3, which would allow ship1 and ship2 to assist each other, but again if you want to try this do it with safety set to green, just in case.
This is wrong. Suicide ganking does not by itself create an LE, and hence you may rep a ship that’s being suicide ganked with safety green no problem. Only if the ship being ganked retaliates (which isn’t possible in the case of a freighter), would an LE be created and repping the victim would no longer be possible without being CONCORDed, which again the safety setting would handle automatically if set to green by deactivating the rep mods the moment the LE is created.