1. This is expected behaviour: "The name of the output file. PowerExchange for HDFS appends the file name with a unique identifier before it writes the file to HDFS. "
You can refer to this doc: https://docs.informatica.com/data-integration/powerexchange-adapters-for-informatica/10-2-2/powerexchange-for-hdfs-user-guide/hdfs-data-load/complex-file-data-object-write-properties/advanced-properties.html
2. Parquet Timestamp is currently not a supported datatype: Parquet Data Types and Transformation Data Types
You could look at processing this data as a string