I would like out QA team to be able to run SpecFlow tests. I would like them to be able to change values and append more scenarios. These appended scenarios will have matching step definitions, so they only need to modify the features.
The QA team does not have access to Visual Studio.
Is it possible to achieve this without using Visual Studio?
We are currently using MS Test but we are willing to use NUnit if that will help.
Yes - there is a 'simple' way.
Since SpecFlow merely generates tests from the text in the .feature files you can use the command line runner of the tool of your choice.
SpecFlow also comes with a command line version SpecFlow.exe and you can chain them together to not only generate and run the tests but also produce a nice test report. Everything outside Visual Studio.
I've written about this here; http://www.marcusoft.net/2010/12/specflowexe-and-mstest.html in an easy step-by-step article.
Hope this was useful.