Yes you should use freescan to make sure you get 0-100% with the throttle, but you do need to leave some slack for the enging expansion due to heat. Adjust the throttle while the engine is hot.
As far as the idle goes. You cannot adjust the idle, the ECU controls that via the IAC. Do not try to adjust it by ear, and freescan will only set the idle temporarily for diagnosis purposes. If you want to check your IAC, connect freescan and allow the engine to idle up to full temp at ~80C coolant temp. The IAC counts should be between 20-40. Otherwise you may have an air leak or other issue.
As far as the idle goes. You cannot adjust the idle, the ECU controls that via the IAC. Do not try to adjust it by ear, and freescan will only set the idle temporarily for diagnosis purposes. If you want to check your IAC, connect freescan and allow the engine to idle up to full temp at ~80C coolant temp. The IAC counts should be between 20-40. Otherwise you may have an air leak or other issue.