1.) I am getting "java.security.InvalidKeyException: Illegal key size or default parameters" exception. Why ?

2.) My Service with Rampart does not run with the Axis2 WAR distribution.

The Axis2 war distribution does not contain axis2-codegen-*.jar which is needed by rampart runtime. Unpack the axis2.war and copy the axis2-codegen-*.jar into the lib directory and re-pack axis2.war

3.) My Service with Rampart does not run with SOAP 1.1

This is a known issue https://issues.apache.org/jira/browse/RAMPART-164

4.) How can i set username and password for the UserNameToken profile in my client application?

See http://wso2.org/library/3190#Step_3._Engaging_Rampart_and_setting_authentication_information

Note: Further FAQs on Rampart available at http://RampartFAQ.com