Presumably your pcf file doesn't have the full path to the files, so maybe you need to do Setup->Simulation files in each test and specify an "include path" to be the directory where the spectre models live?
Probably best to ask TSMC - I don't have access to that particular PDK (given the names of teh model files) - presumably you need to include a section containing par1fn_mc - maybe you can do a "grep" through the model files to see where it is defined?
Hopefully this is covered in the documentation with the PDK too.
Yes, you can include multiple sections from the same model file (you have to have multiple includes, of course) - numerous PDKs work this way.
Asking the PDK provider is the safest bet, because even though I might be able to guess, it's important to know what is "right".
Note that if a model file is controlled via the corners UI, the Setup->Model Libraries in the ADE XL test editor is not used - all inclusions of that file need to be done from the Corners Setup UI.