I have written some topics about tricks and tips on bitcointalk forum and also have some translations about this kind of things.
So now my question is if I copied paste here those post of mine from others forums with the source links is that also act like plagiarism?
Yes, I will include some new word to posting here but it won't be too big.
Since it's yours, you don't need to post a link from another forum, you can directly post it here, but of course, don't just copy all the text; change it based on your preference. No one will accuse you of plagiarism when you make it in the first place.
I see absolutely nothing wrong in duplicating YOUR OWN content in different places. In such case asking people to rephrase their own words would be silly.
Sure, but if the content is something like asking opinions, you could rephrase it, unlike those posts stating facts like charts, list of tables, developer's content like API/codes, etc.