Does the Fritzing software support Basic Stamp 2 and Arduino simulations?
No. Fritzing does not simulate any microcontroller (e.g., Arduinos and Basic Stamp 2).
From 0.9.10, Fritzing has a small simulator which performs only DC analysis. Its main purpose was to teach electronics, not to perform complex simulations. The simulator is in beta and needs to be enabled in the preferences. A blog post regarding the simulator will be published soon.