maybe if i post on every thread i can finally participate in coin discussions
Yeah, no. I'm sure that would classify as spam and get your posts deleted or have you banned accordingly.
Look for threads that have deeper value, such as ones where you can form discussions and actively talk back and forth with others. That is where you can get real thread value from.
On the other hand, assuming you make constructive posts in every thread, you could actually probably do that. But it depends on how well you formulate your posts. More than a few sentences is a good idea, which are related to the topic.
Posting in a few threads with re-post value can be far better than posting in every single thread that exists.