If i reply on a lot of other posts in a short time, is it still post farming? I know I don't mean to "farm or spam", but I'm just super social.
You can reply to threads as much as you want. Post farming is when you write something off topic that doesn't have to do with a certain thread, or writing unnecessary phrases just to get posts. Off-Topic sections doesn't raise your post count. Good luck .
Commenting on many threads is not considered post farming, unless it's obvious that you're only doing it to raise your post count. For example, if someone commented 'Haha' or 'Lol' on five different threads, that'd probably be considered post farming.
In my opinion, the following are examples of post farming: Saying 'lol' or 'agreed' to a post instead of using the ratings available. Constantly posting the same or similar things on a thread, like re-no support on a suggestion for example. When replying to a thread, posting 3 posts (for example) that could all be made one post. There are other examples, these are just a few. You can also read an awesome guide, here.