Hi Pete.
It seems we are in a similar position. I have just started compiling my portfolio and, apart from my lack of Cardiopulmonary experience over the last 10 years, have similar concerns about how to validate a lot of what looks to be academic content (particularly competency 1). There is a physio on the iCSP forum who gained registration after 14 years specialising in Paeds so she may have some useful insights - I'll be e-mailing her tonight.
I would be more than happy to keep in contact with you through the registration process, either through the forum posts or personal messages. I'm sure we would both benefit.
Stu