Hi, thanks for posting!
NCrunch itself won't be responsible for giving off the errors/warnings that you're seeing in your code. This is instead done by MSBuild, where it executes various targets that call into toolsets.
By design, NCrunch does try to match its build with VS as closely as possible. There are some unfortunate limitations that prevent this from reaching 100%, mostly due to the fact that NCrunch needs to relocate and rewire projects in order to sandbox them for build/test execution.
If you're experiencing a situation where NCrunch's build is picking up trivial issues with your code that VS doesn't detect, then this could be due to a platform or configuration difference during the build run. See
http://www.ncrunch.net/documentation/considerations-and-constraints_project-build-platform-and-configuration for more information on how NCrunch handles platform and configuration differently to VS.