The document is an OPC UA specification, all terms that are not OPC UA are prefaced with either ISA95 or UML as described in the terms section of the specification, so I see no conflicts with regard to terms in the highlighted section.

1) But the use of ISA-95 (reference to the standard) and ISA95xxxxx for terms should be consistent. All instances should be checked.

This item
"4.4 Modeling Approach of ISA-95) reads: "Map all ISA Classes and ISA Objects to OPC UA ObjectTypes, creating OPC UA ObjectTypes as needed. Again ObjectType need only be created for Objects where multiple instance of the Object will exist, otherwise simply creating an instance of the appropriate ObjectType (EquipmentType, PhysicalAssetType).""

Needs to be cleaned up - It should be broken into two sentences one for ISA95Classes and one for ISA95Objects. It is misleading and hard to follow as it is structured

2)This statement in the writeup
"In Figure 13 the ISA95Class is mapped to ObjectType only. From that, the reader concludes, that any ISA-95 Resource Category is realized by a Node of NodeClass ObjectType. However, given that this is correct, that would be a contradiction (am I getting something wrong here?)."

The ISA95Classes are mapped to ObjectTypes, ISA95Objects are mapped to ObjectTypes or Objects as the figure indicates. Cleaning up the previous highlighted issue may help, and making sure that all of it is consistent.

3)
The "3. Information Model Diagrams" Issue points that the wording for PersonType with regard to PersonnelClassType is not correct. Instances of xxxClassType where not expected in this mapping. Clean up the PersonType definition with respect to PersonClassType placeholder (point to type or instance)

4) the item "4"
" Clauses B.2, B.3, B.4, and B.5 do not list any ISA-95 model element of type ISA95Class, or any OPC UA model element of type ObjectType.
This would not be a problem, if left alone – but the information model examples provided in the specification show that ObjectTypes are in fact used a lot. "

The ISA-95 model mapping table lists the general type of an item (i.e. object is not the OPC UA defined term Object) the choices are reference, datatype DataVariables or objects - the model indicate the type for the item, so I'm not sure what you are expecting different in this table?

In B.3 (and C.3) the ISA-95 model element Personnel should be named PersonnelClass."

Agreed this will be fixed

Item 5)
"In a “mixed mode”, where a single instance of an ISA95Class is represented by both a Node of NodeClass ObjectType and a Node of NodeClass Object:
 Must there be a restriction that there may exist only ONE Object (much like a singleton pattern in software engineering)? Because conversely, how would the constellation depicted in Figure 2 map back to ISA-95?
Or would one have to decide between realizing an instance of an ISA95Class as either an ObjectType or an Object?"

The model supports both instance and type mapping. Figure 2 describes something that could easily happen - a subtype of PersonnelClassType for Operator is created (adding appropriate properties) and then two instance are created one for unit 1 and one for Unit 2 - they would both get all of the items added in but the values of some of the properties might be different. I'm not sure what we need to do for this issue - provide an additional example? or more text?