to answer your question about B8: the question evaluates two aspects, whether:
1) the dataset is in a machine-readable format
2) the dataset is in a format usable with a free/libre/open source software.
Both have to be fulfilled. This means that our list of formats includes only formats that meet both requirements so we can give a full score for open and machine-readable formats. PDFs do not meet the criteria of machine-readability (You can find more info here).
Please use the comment section on the right side of the question text to tell us whether the data are provided as PDF.
To your second question about B9: You are right. The usability of a file format is determined by 1) the type of data contained in the file, 2) your use case of the data. For instance, if you submit data on draft bill content and votes on a bill, let us know what your use case is, and how easy it is to use the data for this specific case (for instance do you need to extract information from a pdf file first, etc.). Base your assessment on these two steps. Please document your approach in the comment section, this is very useful information both for our reviewers and us.
Please do not hesitate to send any further questions if anything is unclear!