I’m trying to learn more about the SDF base and thanks in advance to anyone good enough to help answer the below questions & provide any other relevant info.

SDF flying is only for American (not United), right? (i.e., those based in SDF are NOT eligible for UA’s Aviate program, correct?)

What is the relative seniority of SDF to YV’s other bases for both CA’s & FO’s? (APC profile data is jumbled up and likely dated at this point anyway)

Is the CRJ-900 the only equipment flown by SDF-based crews?

Roughly how many flight crews are SDF-based?

Are there any significant changes expected or possible to the SDF base as far down the road as can be seen currently?