North Star,
The OP is asking about pathways and stairs between buildings on a campus, so access to public ways that are not the designated MOE would still need to comply if newly installed.
What ever was installed prior is subject to when permits were pulled, inspected and closed with C/O, if they were even required when built.
As to the OP 2nd posting, if the sidewalks are interrupted with single changes in elevation between 2 landings, then no handrails would be required per PA IBC.
The min landing is 48", thus as long as each questioned elevation change, "landing", meets the 48" Min, then though it looks like a stairway, by definition it is successive landings with no tread between any of the landings, thus no handrails required.
However, for liability reasons one would highly suggest adding compliant handrails.