Yes it is a good way to create unique content, make sure that you do not copy exact words from the original content. And always check your copy with a plagiarism software like Viper or Copyscape, another best way to check plagiarism is via Grammarly Premium; you get to check grammar and many other things with it. But I would suggest you to start learning a lot and then apply what you have learned and then write from your experience.
In my opinion, it's not the right way to write unique content. Your traffic depends on how your visitors would react on your content. If all your articles are just copypasta from other blogs, your visitors will leave your website as soon as they realize that there's nothing new or engaging to read about it. As it was already mentioned, you could check your writing for potential similarities with plagiarism checker, for example Unplag .com. Content Rescue is another program for plagiarism detection (and a few more were mentioned above). Such software compares your articles with already published materials and show the percentage of similarity, so you could later rewrite similar passages and not harm SEO of your site.
Oh, that's another story! Sorry if I misunderstood you. I could advise you to think about new points which you could add to your article. About some new fresh ideas. If something has changed since the publication of the post that gives you inspiration, write about that changes. E.g. There's no sense in writing about Google Authorship or about other outdated things.
Reading a lot of other posts may give you more ideas on what you can write later; however, you still need to use your own words. Try to find synonym words or paraphrase what you have read and try to make it flow smoothly from one to another paragraph. What's good about this is that when you use your words, it will make you much easier work and save time in translating it into English. Hope this helps and you'll get outstanding and unique content in your website.
If you are doing an SEO blog I assume you have experience and knowledge in SEO? If yes - then writing unique content is very easy. Just think of the lessons you learned, mistakes you made, things that worked and those that damaged. Write a about that. If it will come from your personal experience, spiced with some examples - you will get your users intrigued. They will read, stay on your site, share it, come back. Then your blog will get ranked high and you could write posts on "Why writing interesting and unique content is good for SEO"
Hi there, This is a great way to create new content out of an existing content. But, surely not a way to optimize your site for search engines. Doing activities like on/off page SEO and blog posting/commenting will surely help make your way up on search engine results. BUT, let me tell you it takes time. So for now, you can focus on creating fresh, interesting and relevant content, and worry about the SEO later. Good luck!
Yes, its a right way to write a blog if you have not much knowledge of that topic. but make sure you write it in your own words. Otherwise its a perfect technique to use.