Many of us here have had no problems with SAI cast parts.
But some have had problems.
If the bolt serial number reads
0000000-SA
F00000
than it is forged. That's the "F."
The Operating Rod, some of the trigger group, and probably the rear sight parts are cast.
If you're really worried about it, replace the Operating Rod, Operating Rod Guide, Extractor, Firing Pin, and Hammer with USGI. Maybe even replace the entire Trigger Assembly.
As for differences between the standard M1A and the "Scout Squad," besides barrel length and gas port tuning differences, the only major difference could be a heavy barrel. Lock the bolt to the rear and you should be able to see the rear of the barrel where the Operating Rod was. If the barrel outside diameter is the same (approx. 1.1 inches) for more than a few inches, then it's a heavy barrel.
Hope this helps.