To catch the explorer it means to tell everyone when and where he arrives.
Sure, and that applies to traders and miners and bounty hunters and mission runners too. The last time anyone shot at me in Open, despite that being the place I spend almost all my in-game time, was I think almost two years ago ... haven't even had someone try to interdict me for over a year. It's not a very likely thing to happen - it's just potentially catastrophic if it does.
Could you give me some figures, realistically how much a sphinter or merchant can lose per voyage?
I don't want to make Elite safe, it doesn't work that way. I just want to increase the proportion of people fighting
A laser miner could have bulk mined Platinum, say 500t in a big ship, sale value around 300k/tonne, so that's 150 million in potential profit gone if destroyed compared with a ship rebuy probably in the 10-20 million range. Core gems can be around 1 million/tonne in ideal circumstances so a ship full of those might be giving up over half a billion of potential profit (even at 100% rebuy, the cargo is more valuable than the ship!)
A bulk trader shipping Palladium or Tritium could have bought at around 40k/tonne and be carrying 750t - they'd actually lose 30 million credits if destroyed (rebuy maybe 10 million credits) - and also miss out on another 15 million credits of potential profit.
In any case, neither is going to stick around and fight if attacked by a player - a mining ship has to give up too many hardpoints to mining equipment to be able to fire back effectively against anything but a weak NPC, while the trade ship might have a full weapon set (though on the T-x series, that's still not very much) but is going to have relatively low shielding and armour.
Even my multirole Krait II - which is perfectly capable of blowing up most NPCs and where the rebuy
would generally be the most expensive part of losing it [1] - if you interdict with any sort of combat ship I'm just going to high-wake out because while I've got decent firepower and enough shields that you can't stop me leaving, I have nowhere near enough defense to endure several minutes of PvP, so I may as well skip to straight to the part where you "win" by getting me to flee.
(Rebalancing combat ships way downwards so that the gap in performance between a freighter with basic shields and weapons and a fully-armed Corvette packed with defensive modules was minimal is firstly highly unlikely - why bother fully engineering a Corvette if it only gives you 10% extra firepower and defense over a trade T-9 - and secondly wouldn't help: I can assume anyone choosing to interdict me outside of an arranged duel thinks that they can beat me in a fight, so why bother taking a chance that I've met someone overconfident - running immediately is still the best option for most defenders)
[1] The rebuy is under 5 million and I have around 5 billion in spare cash. Do I actually care about having to pay a rebuy? No. Still not going to stick around for two minutes to be shot down without seriously denting some Cutter/FDL/Mamba's shields, though.