Did you forget, or just didn't know about "reverse cheating"?
It's when Hacker H uses the program to modify data in ED memory, to make Player P (his opponent, remote player) getting zero damage from shots made by H.
Then H goes to FDev with video record showing how P receives zero damage from tons of shots, and FDev bans player P.
Do you want this again? Potential risk to get a sudden ban after any PvP engagement in Open, being totally clean in reality?
That's why i always tell that p2p is absolutely inappropriate for any kind of MMO (of course, assuming that cheating is bad for that MMO). If you don't control server-side process, you don't control anything, you cannot even identify / distinguish reliably cheaters and fair players.
So, forget about this. No dedicated servers -> no consistent multiplayer. Just deal with the fact that really ED is a singleplayer game, with some coop capabilities.