I used to have Cushing's disease. I was resolved by pituitary and adrenal surgery.
I had low ferratin, low D too - this is pretty consistent with my Cushie buds.
As for the SED, it tests chronic inflammation - I personally did not test high with that, but my CRP was super high (like 42, the range is 3) and that is another inflammation test - but others did - so this is another thing that is consistent with Cushing's.
A/G ratio should be high with chronic inflammation - but low ones show up in auto-immune diseases - I don't remember and this is not one we talk about.
Alk/phos - I have had some high tests and they told me I was forming bone. I have no idea - and that test is not one that is run much.
I will say that a lot of people with Cushing's do have a fatty liver so some liver tests may be wonky.