Should I be considering flushing the cache from time to time? Or I can cache all my API responses?
1. Should I be considering flushing the cache from time to time?
No. Because $cacheFactory will destroy all the data once the session has been closed. Or if you want to flush manually then you can use destroy method.
destroy() - Removes references to this cache from $cacheFactory.
removeAll() - Removes all cached values.
2. I can cache all my API responses?
This is possible in two ways as follows.