Baud rate change slows down void loop and stepper motor speed??

Other Hardware LEDs and Multiplexing
8

According to the documentation for currentPosition()

Returns:
the current motor position in steps. Positive is clockwise from the 0 position.

There's no mention of reporting the position by the serial port and that would be pretty strange if it did. Where did you get that info from?

Doesn't this

AccelStepper stepper(1, 9, 10);

use the serial Tx pin? If so that's not a good idea.

Rob