clean of unnecessary checks, imports, calls

[marksmayo]

Describe your change:

places where cleaner code is better (pylint identified) simplifying return (bools) replace type with isinstance

Checklist:

• [X] I have read CONTRIBUTING.md.
• [ X] This pull request is all my own work -- I have not plagiarized.
• [ X] I know that pull requests will not be merged if they fail the automated tests.

Had issues with validate-filenames failing on pre-commit, looks like on windows it gets confused with the \ vs /, so I no-verified just that stage.

[marksmayo]

Would appreciate help from reviewer - the failed test is on a file I didn't touch, and I don't believe I've modified dependencies? Looks like it's actually a problem with the runner not finding a config?