Hello!
I'm part of the team behind a static code analyzer for C#. We often use our tool to analyze open-source projects, detect potential issues, and share our findings in articles. We’ve recently published an article summarizing several issues detected in the NBitcoin codebase. I hope this overview will be helpful. The article covers only a part of the findings. I'd recommend running the analyzer yourself and seeing the full picture. If you're interested in using the analyzer, you can request a long-term free license for open-source projects.
Good luck!