Does “Clear Data” also kill the app?

Clear Data does kill the app, and always has.

"Force Stop" has gone through various iterations of meanings. It used to mean to just kill all processes and services, and clearing data would also do the same as a force stop. There were also older iterations of the platform that were not as good as figuring out when to disable the button, which is probably why you are seeing it remain enabled in 2.2.

However in 3.2 I believe the meaning of "Force Stop" change to put the application in a state where it would not be able to run until the user had done something to explicitly start it (such as launching it from launcher, selecting it as an input method, etc). When that change was made, "Clear Data" continued to just kill the processes and stop its services, so the app was not in the full stopped state so the button remains enabled.

yes, when you click the ClearData button in Settings-->Applications-->Manage applications-->[MYApp]Tap the MyApp.. Click the Clear data buttonWhen you click the clear data button then the data will we erased/delete.....obviously when delete the data then App will go to force close