As a show-watcher I am confused about something, could you help ?

I have a few questions about the San-Ti, maybe a book reader could clarify a few things, thanks.

1) why is the first message from a San Ti pacifist warning not to contact them if their whole race thinks as one and don't keep secrets/lie ? So if one San Ti know about the humans wouldn't they all ? Therefore the warning from that San Ti seems kinda of pointless. Like what's that San Ti gonna say if another one asks " hey bruh you found any messages from aliens ? " They can't / don't lie.

2) why are the San Ti telling the humans about the syphons ? Seems kinda of stupid to reveal some of your best weapons/ recon units. I know the humans can't really do anything against the syphons but still seems like a stupid thing to reveal it since by the off chance we humans can come with something against them.

3) How long have the San Ti been messing with our science ? In the show I think it says since the syphons got to our solar system so doesn't that mean we still have some good info to work with like info about sub atomic particles ( quarks and all that shit - or is my A level physics useless lol )

Bonius question) why everybody here hate Auggie lol ? She is cool, smart and sticks to her convictions. I like her alot. I kinda hate Saul. Also hate what happened to Jack- he was my fav.