SSL questions

This is my first app that uses SSL so I have some n00b questions.

1. Do I need an SSL certificate on my development machine to work with Paypal and other services that offer testing environments?

2. What do you have to do when the app's clients all have a separate subdomain?

3. I realize that you can generate your own ssl CSR, but it will be flagged as unauthenticated. Does anyone do this? If not where do you get your CSR from. I have heard bad things about godaddy. Does anyone have any experience with them? Then there are places like verisign that have the large fees.

4. The only decent article that I have been able to find is http://www.buildingwebapps.com/articles/8-using-ssl-in-rails-applications. Unfortunately, there is no notes on working with it on the dev machine with mongrel. Does anyone know of any other articles?

Thanks for the help.