What you've asked for is essentially a mechanical engineer's dissertation...it's pretty gnarly stuff for the layman to tackle. I'll give you an overview though, or at least some info based on what the issues appear to be in the data.
For the first topic, you might read this for some background:
https://forum.hptuners.com/showthrea...l=1#post616505. I posted that a couple weeks ago to give a basic who's who of idle calibration. It's based on older engines/technology but the physics remains the same. That said, based on what I see in the data I think it's good to remember that your vehicle has a variable displacement AC compressor which means different torque loading based on how hard it is being driven. It also multiplies the number of torque model operating points that have to be spot-on to avoid those RPM flares. Looking at the beginning of the first RPM flare at 14:13.200, you can see the controls preparing to do exactly what I described in the previous post. If you look at the predicted torque, you can see it jump up 12ft-lbs really quickly. The throttle and MAP are following this request. So, predicted torque is essentially a feedforward estimate at the present operating conditions, or an 'unmanaged' torque potential based on the output of the calibrations you've entered into your torque model. Now the predicted torque is only an expectation from the controller, basically a target to be able to reach. Then the immediate torque comes in and provides final arbitration over actual desired torque delivery based on any other requestors that may want less torque. It may help to think of predicted torque as a slow path, ie airflow and the immediate torque as a fast path control like spark or fuel. You can make torque much faster with a change in spark than you can with a change in airflow because air moves slowly, especially at idle. Now the goal here is to have a nice, smooth AC clutch engagement. Customers don't want to feel it and the torque reserve makes this possible. So you bring in more airflow, pull out some spark via the immediate 'managed' torque request and you have a reserve ready to ramp back in as the AC clutch comes on. Typically this achieves a negligible impact to idle RPM but in your case, as you mentioned...the problem is the torque model. A snapshot from your file...
torque model inflection.PNG
The point the cursor is hovering over shows the problem - an inflection in the spark response. It shouldn't spike up, especially not when your idle speed is too high. And it isn't a transition to main spark because the state variables you've got in your log don't change to 'torque'. Since you've likely noticed there is no idle spark table, you know that idle spark value is coming from the torque model. There are quite a few nuances to get the idle spark value from the torque model as it is technically the inverse of that model, which is technically a blended array of models where the APC or airmass model is more or less primary. So the immediate torque request is targeting -26ft-lbs at 732 RPM and 0.186 grams in the cylinder. Now attaching your airmass torque model vs a stock 2014 Silverado airmass torque model:
VT_mod.PNGVT_stock.PNG
I can see how it may make sense to decrease the modeled torque output at lower RPM. Your cam moved the torque curve up, so it'll be a little soggier on the bottom end. Have to keep in mind though, this isn't a VE table...you've got mass on the Y axis, not pressure. While torque will look a lot more like VE with MAP on the Y, it's not the same for air mass. Those tables depict the torque output with the assertion that all of that air mass is actually getting smashed into the cylinder, manifold pressure notwithstanding. And, since you'd be doing it with less pumping loss, the torque output is actually higher in your case with a reduced DCR/lower effective displacement at low RPM. What ends up happening with your model is when the inverse APC model is parsed for a spark value, it doesn't move as far down in terms of spark because you've told it that it makes less torque with the same air mass compared to stock - now in order to meet that same -26ft-lb torque request, it is able to select a higher spark advance (or higher air mass, depending on low level arbitration). Looking at that spark advance creeping up and with an already low APC, the controller is adding spark and driving your idle up.
While there is no suitable way to calibrate this on the street (yet), you should work on that airmass model more. I'd put that back to stock and then add a little more torque in the area where you've reduced actual low-end torque. If you could actually get that air into the cylinders, that cam would be doing it with less pumping effort. The MAP model may benefit from revision too, but one at a time.
This ended up being far longer than I anticipated, so I'm gonna stop with just question 1 for now lol. I have a feeling making those changes will end up helping numbers 2 and 4 though due to the likelihood of hanging the throttle open rather than adding spark to meet a higher torque value. I also have a solution to 3 as well, but for another time. Hope this helps.