- No, there is no "special" rate limit besides the two regular limits. From the docs:
The general limit is 5,000 API calls per hour, but if the API call is marked as "Rate limited" in the API reference the call is deemed resource intensive and a lower rate of 1000 calls per hour is enforced.
- You can use https://developers.podio.com/doc/comments/get-comments-on-object-22371 to count comments.
BTW: There is a hard limit on the number of comments you can create. I don't recall what the limit currently is, but maybe someone else does. (In case you figure that out, please post it here for others to find).