Hi Squirrellypoo,
Sorry to hear about the relapse with added PNH. PNH and AA do run in pairs for some. And from what I understand, many with AA have some level of PNH. It's just that it's so small it does not matter. John gets checked for it every year at his follow up visits at Hopkins.
So to answer your questions:
1 - There are a few AA patients from the UK who have posted on the Aplastic Central forum. You may want to post there also to connect with them.
http://www.aplasticcentral.com/
2 - Same regarding runners. There have been some AAers in their 20's who were very sports oriented who have recovered and been able to incorporate sports back into their lives.
3 - I don't think you can ever say "cure" when it comes to AA. But certainly, in your case, after 20 years, it sure looks like a cure. Most call it a durable remission. And I would say that you DO have a much higher probablity of getting AA again than the general population. Like all autoimmune diseases, they can come and go and come again.
4 - Again, there are a couple of other AA'ers with a high PHN clone at Aplastic Central. There is fairly new drug called Soliris that has been approved for PNH in the states. It's usually not used until your PNH is pretty high though. Also, check the PNH section of this forum.