idle
OK, since no one jumped in, I will try.
I am assuimimg Holley carb, but about the same for any carb really.
You turn each screw in and out until you get the highest vacuum reading or the highest rpm.
If the idle gets too high, just back off your main idle screw and continue.
I like to use a vac gage since I have a big one and it is easy to see changes.
If you can turn in the screws all the way and it makes no difference or is highest reading with screw all the way in, the idle curcuit is not working and is trying to ruin on the main curcuit.
The throttle blades could be too far open and the idle slot is too far exposed.
As far as idle being off affecting full throttle performance, it would have a minor effect at best.
Now maytbe someone will ad some good advise.