IFT3 was technically suborbital, but only barely. Like a couple hundred km/h short. Literally a couple of seconds longer second stage burn would have put it into a stable orbit. Or the same velocity just with a lower apogee. They intentionally left the perigee just inside the atmosphere so a deorbit burn was not required. This is also the plan for IFT4, iirc. I think they are talking about the bellyflop/suicide burn. It was not planned on IFT3, but is for IFT4.
Both the booster and the ship have attitude control thrusters that you could see firing during the live stream of IFT3. Early prototypes used nitrogen cold-gas thrusters, but were planned to be upgraded to methane/oxygen hot-gas thrusters at some point. I don’t recall if/when they were.