Pain is subjective, but still, he's getting murked a LOT anyway in pretty goddamn terrible, painful ways. Remember, there's that one time he just falls asleep and then wakes up without any pain because a curse killed him without him realizing it. So it isn't established that dying hurts a lot. All it really establishes is Subaru can go OD on sleeping pills and die without any pain. When he wakes up, even he doesn't realize he died for a few minutes and is extraordinarily confused. So it doesn't have super painful effects. He mind breaks in the series not because of dying but because he sees everyone he cares about die MANY MANY times in a row and has NO IDEA what to do about it. Which is what makes him want to just fuck off with Rem.
I'm not saying he needs to be a big player. But all he does is need to be cogent about his reaction speed and when to do it. The trigger itself seems to at least be 3 days or so. If you notice in the anime, he goes back 3 days very consistently. So it isn't an overnight thing at all, and if you time it properly you can basically guarantee your checkpoint. Still, with a three day lead, you have to be a real fuck-up to guarantee a bad end.
To be fair, he doesn't really need physical evidence. All he had when fighting the white whale was a picture and even that didn't convince anyone. What did was the lie-detector lady. Just drag her along everywhere. All he really needs to do is get a few people to trust him a lot (which is pretty fucking easy to do when you can time travel). So eventually you're not even going to need evidence. Yeah, he can be beaten in a one-on-one, but when you can time loop, who cares. You've got multiple days to build allies and plenty of time to get information you need.
I mean, yeah the skill is obviously nefarious but he does literally everything to provoke it. And so far so good with it. Its basically given to him by an evil God. Evil forces don't generally just give things to people out of the goodness of their heart. Not to mention the witch clearly wants him alive for some reason, so wouldn't just go, 'ah, you know, I didn't tell him the rules so whatever. He dies forever' The only time the Witch 'tells' him is when he tries to tell other people and she grabs his heart like 'Don't do that'. So its quite clear if he was pushing it with the skill, she'd give him some other warning. Logically, he hasn't figured out the checkpoint conditions. That's about it. But if he dies one time, he knows where he starts back off. Dude should be counting days and hours after every time he dies and resets, which he doesn't (because he's not smart) so that's his own fault. But to me, it seems on a pretty steady 3 day clock. That and its provided by something supremely evil but its already been established that it will set boundaries for him, there's little worry if he's going to over step them without any sort of hint or warning. Not to mention said supreme evil doesn't have any current way to effect the world and doesn't seem to want to take over his mind or is clear if they even can or want to. It isn't like its stealing his soul or having any visible effect on the world around him at all, other than the changes he dictates. It is basically given to him to be used.
The only real problem is the checkpoint one, which he has paid very little attention investigating.
R; Anyone can tell a Zulu from a Swede. Anyone claiming to be an "expert" who can tell a Korean from a Japanese as confidently... not buying it.
