I am planning to do some extra coding at home on a project from work, and rather than try and justify them giving me a copy of VS2008 pro, am I able to open VS2008 Professional created C# projects from C# Express?
Any changes I make, I will simply load the changed .cs files to VSS, so I don't need the project to save back to a valid VS2008 format.
I am aware that some functionality not be available to me in Express, but is is largely POCO and ADO database work I will be doing.
Yes, you can. If you have mixed solution, though, you might have to install all versions of VS Express and compile the projects bit by bit.
E.g.: VS-solution with C# and C++ - project. VS Express will either compile the C# OR the C++-project. So you'll have to compile first the projects the other projects will depend on and then switch.
Little bit awkward, but nothing more.
Short answer: "Yes, we can".
.csproj file are just msbuild file with special targets for C#.
I think it depends on the type of project. I believe Smart Device Projects, or projects with Crystal Reports might give you trouble opening since they are not supported on express editions. But if its simple projects you shouldn't have a problem
While you can open projects, I believe there are file types and project types that you cannot open. For example class diagrams are not available in the Express versions. This probably does not apply to you but if you are working with a certain project type like a BizTalk project, those are not available in Express.