Yes, the 7AT always matches revs correctly, whether it's shifting on its own (D-mode), or you are shifting (M-mode).
And yes, you can use the shift knob instead of the paddle shifters if you want. It works the same as most AT's with a manual mode (sequential-like, with a forward click being upshift and a rearward click being downshift). It's probably better and easier to always use the paddles if you can get yourself used to it. I have 6MT habits so I'm constantly putting my hand down there and using the stick instead, then catching myself doing it and switching back to the paddles. It will take a while
If you think the 7AT is speeding you up when you downshifted intending to decel, it's not the 7AT, it's you. Check out what you're doing with the throttle. You can downshift for accel or downshift for decel, and the difference is your throttle input at the time.