Hi Harold

Here's a part of the answer to your questions

1) Feeds are still currently being served by Feedburner, it's just the counter that is broken

2) We don’t know whether this zero subscribers issue is temporary or not

3) The API is being shut down Oct 20th this is not the feed delivery service, just the API.

4) If accurate stats are important to you, switch to another service like FeedBlitz:

a. Why: http://www.feedblitz.com/feedburner-shut-down-the-facts-and-tales-from-the-front-line/

b. How: http://www.feedblitz.com/the-feedburner-migration-guide/

c. Results: http://www.feedblitz.com/feedburner-feedblitz-case-studies/

I work for FeedBlitz and we'd be happy to assist you with any support you need to migrate your feed and your email subscribers.