How to add custom fields in OIM Self Registration page

I have read this article  which talks about adding custom field (email confirmation for 2nd time) in the Self Registration page. The scenario is simple:

To add field Confirm Email for 2nd time in the Self Registration page. This behavior can been seen in many of the websites. So, what would you do when you are using OIM for this purpose? By default, OIM supports adding custom fields to custom self registration page by modifying the FormMetaData.xml file. However, the problem arises when you want to add logic to the form to have the Email confirm field match the Email field. This can be done easily (either by adding javascript or by adding custom code) if it is a custom Self Registration Page and not OIM self registration page. The workaround is so simple: Decompile the tcSelfRegistrationAction.class java file deployed in the XellerateFull.ear file and copy the function of confirming the password and change the field name to email. 

Identity propogation in a flow involving OAM, OWSM and OSB

I have recently gone through this article and found very interesting.
The scenario is this:
OAM is protecting a Portal UI application which is making WebService calls. WebService is protected by OWSM and the communication is made through OSB. Two approaches were discussed in detail in that article.