SY flies out of MSP Terminal 2, which is essentially a separate airport (shares runways though). Make sure to tell your taxi which airline, as it's not the same as Delta.

I can't really comment on lines (which day?), as I pretty much always fly out of MSP on Sunday evenings where it has consistently been dead as a doornail after 5pm. Security is pretty standard; there's an F line and a pre-check line but not one for pax with both. I'm usually from the curb to the gate in about 5 minutes, but ymmv based on time of day.

SY boards early (BPs usually stamped T-45 or earlier) and they claim check-in closes 45 minutes before departure. I usually show up at the airport about 60 minutes prior and have a little bit of time at the gate. If you're not a veteran traveler I would probably recommend a bit more breathing room than that, but I doubt a whole lot is necessary. T2 is small and efficient compared to the main airport.