You can see the plaster, tile, coping and deck, but none of that really matters in diagnosing the problem with the concrete.
To diagnose ASR, you have to be able to see the actual gunite or shotcrete.
I would want to see about 10 square feet of the gunite structure to see if it has the characteristic cracking pattern.
At that point, you can probably get a preliminary diagnosis that it is probably ASR or it is probably not ASR.
You would also need core drilled samples to be taken for analysis to determine the definite diagnosis.
I would want an engineering team with structural engineering expertise and specifically concrete structures and geotechnical engineering expertise.
In my opinion, if it is advanced ASR, the only remedy is removing and replacing everything.
If is not ASR, then the remediation plan will depend on the diagnosis of the cause of the cracks.
You should check the pool for being level by checking to see if the water level is exactly the same around the entire perimeter.