Would it be correct, for better understanding and simplicity, to classify (split) all OID Identifiers into two main categories:
1. OIDs providing status (info) about something (provisioning, load, frequency,etc) Those OIDs are read-only access.
and
2. OIDs that allow to set or change specific parameters. Those OIDs are read-write access.
That is correct
There are three other kinds of OIDs
not-accessible -- usually containers for other readable or writable OIDs
read-create -- part of a table that allows creation of conceptual table rows, when creating a row in the table these are usually the required rows for creation
accessible-for-notify -- these oids only can be used in Notifications (traps)
In the Docsis world there is another psuedo type and that is OIDs that can only be set in the config file, after the modem is up they are read-only or not-accessible