Does Powershell provide a 'datatyping facility' for the contents of Files? or is it just values returned from Powershell defined objects or methods?

Contents of files are, depending on how you read them either a byte[], a string or a list of strings (lines). You can run them through parsers for JSON, XML, CSV or whatever else is handy to get actual objects. In the CSV case there are even cmdlets that work directly with files (Import-Csv, Export-Csv), for XML I usually use [xml](gc file), more general there are the ConvertFrom-* and ConvertTo-* cmdlets, e.g. for JSON and CSV.

See my reply to omaranto.