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.