warning that might contains spoilers for undertale so please play the game before reading this

I was thinking about something, here's the thing: in the genocide route sans said:

our reports showed a massive anomaly in the timespace continuum

OUR reports, that can only mean that he worked with somebody, who I assume is Alphis. We can see that he knows about resets and for that he lost hope:

you can't understand how this feels. knowing that one day, without any warning... it's all going to be reset. look. i gave up trying to go back a long time ago. and getting to the surface doesn't really appeal anymore, either.'cause even if we do... we'll just end up right back here, without any memory of it, right? to be blunt... it makes it kind of hard to give it my all.

In pacifist route he never mention something like that, but I'm certain that he already knows something because he understands it by the look on our face:

wait a second. that look on your face while i was talking... you've already heard my spiel haven't you? i suspected something like this. you're always acting like you know what's going to happen. like you've seen it all before.

then he tells us a secred codeword that we have to tell him if we are timetraveler. If we do he doesn't act that surprised, like he suspected this (as i said).

So my questions are:

1. Do he really work with Alphys? 'Cause if he do, then Alphis would have known thant things too, so why she doesn't act like him?

2. Since when he knows about anomalies in the timespace continuum? Because he's lazy since a long time, even Papyrus says:

IT'S BEEN EIGHT DAYS AND YOU STILL HAVEN'T... RECALIBRATED. YOUR. PUZZLES! ... YOU GET LAZIER AND LAZIER EVERY DAY!!!

that could only mean that he knows for a long time

3. If he knows that everything is going to reset, then why believe in a timetraveler and give him the key to your workplace?