I am using Rational Rose Enterprise Edition 7.0. It does not give options for importing C# code for reverse engineering the design. Any add ins can be downloaded?
Or I am using Visual Studio 2010 Professional (not Ultimate edition). Is there an easier way to generate the sequence / collaboration diagrams from the code?
Doxygen will help to generate the class diagrams and API documentation. It also has options to generate Collaboration and other UML diagrams using Graphviz dot.