Are you using the handheld or a laptop? Laptop is really needed as the handheld is hard to tune with.

The default afr and timing tables are only to get it to start. Once you have a good afr table you can have it self tune the fuel map. They also need to be smoothed, default has big jumps. Use 2d tables and not the simple ones.
IAC position at hot idle should be 2-5%. If you have a tight torque converter that drags rpm lower than in park you have to tune it in gear. IAC will make it surge if thats the case because it cannot hit target idle constantly.

I have a stock 6.1 running terminator X, I use the stock DBW throttle body I modified to cable and use a ford PWM IAC.

I started with this video, will give a good idea how to play with the timing and afr maps. https://www.youtube.com/watch?v=tGlPoWK2kf0&t=1113s

I have 24 as max timing.