Hi @BigRoy,
Please check our Support Procedures in regards of the question structure, namely:
Singular Question: The initial posting of a support topic must contain a singular question. Do not ask ten things at once, that makes it extremely hard to answer topics. Break up your questions into multiple topics. Asking follow-up questions is allowed but they must be bound to the initial subject.
Singular Subject: From all this follows that a topic must have a singular and sparse subject tied to a specific problem. 'My Nodes API Questions' is not a valid topic as it splits up into too many subtopics. A valid subject could be 'accessing node attributes' or 'traversing a node graph'. One could for example first ask 'how to get the name attribute of a node?' and then ask a follow up question about 'how to get the icon attribute too?'. This specifically applies to plugins, just because you have two problems with one plugin does not mean that they should be asked in the same topic.
Regarding you question, there's no high level API that allows you to get a list of all files you've mentioned at once. This effectively means that not only do you need to access this yourself, but you also need to do so for the render engines you'd like to support, as these are likely going to differ among them.
Specifically for the Redshift AOVs and output files question, please check related threads:
get the names of redshift multi passes AOV names from the render settings Add Expression Value in Render Settings Save PathAs for the takes, the only application where they make any sense is the Render Queue. If you're not using it, it's only the active take that's being rendered. Of course you can deal with it by using SetCurrentTake function.
I suggest you keeping this thread for the "render output files" part of your initial question and encourage you to make separate postings for your other questions that diverse from this topic here.
Cheers,
Ilia