RDF Data Cubes, AttributeProperty, units of measurement & QUDT

Question

I'm doing some work with RDF Data Cubes vocabulary for publishing time-series of various data, among others sensors. The measurement of the sensor is taken at a specific time at a specific station.

Both time and station I will model as qb:DimensionProperty, the measurement itself as qb:MeasureProperty. I would also like to state what unit the measurement is in. In this particular example it is atmospheric pressure at the height of the station. My understanding from the spec is that this would be modeled as qb:AttributeProperty.

In the description of the data structure I would have something like this:

<dsd/prestas0> a qb:DataStructureDefinition ;
    qb:component 
        [ qb:dimension  <stn>; qb:order 1 ],
        [ qb:dimension  <time>; qb:order 2 ],
        [ qb:attribute <unit>; qb:order 3 ],
        [ qb:measure  <prestas0>; qb:order 4 ] .

<stn> a qb:DimensionProperty ;
    rdfs:label "Station°" .

<time> a qb:DimensionProperty ;
    rdfs:label "Time" .

<unit> a qb:AttributeProperty ;
    rdfs:label "Unit" ;
    rdfs:comment "The unit of the measurement" .

<prestas0> a qb:MeasureProperty ;
    rdfs:label "Measurement" ;
    rdfs:range xsd:float .

# Units in use

<hPa> a qudt:Unit ;
    rdfs:label "Atmospheric pressure (hPa)" ;
    rdfs:comment "Atmospheric pressure on station level" ;
    rdfs:subClassOf unit:Pascal .

As you can see I also created an instance of a unit, called <hPa>. In there I use rdfs:subClassOf to subclass from QUDT unit:Pascal.

Now my questions:

• is my understanding of using qb:AttributeProperty for the unit correct?
• Is it fine to sublass from QUDT the way I did? I am aware that I have hPa while QUDT defines Pa only so I would probably have to change the data accordingly
• Can I in general simply use units from QUDT directly (in terms of their URIs) if they do not need a specific tailoring like I did in this example?