1. SXM yes, US, slowly. All manned terminals still accept a swipe card, but fraud is at merchant risk.
2. It's the same terminal. In SXM most (all?) Chip terminals also have a swipe slot.
3. That's a definite maybe. Chip-and-PIN cards will work. A small number of Chip-and-Sign cards may also work (Most don't, I have one that does).
All cards still have a mag strip, and all cards will likely work at any retailer, at least for the next year or so.