Hi Bondra,
I want to share my experiences according to your questions.
- Ghost is open source so you also can install a 5$ droplet on digitalocean.
- I have also same issue related to this problem then i was created a post about that. You can find some solution there: Is there any pop-up solution to collect emails for newsletter? - #4 by simay
- Ghost uses markdown editor its more simple i think. Wordpress may cause some html problem while creating the content so ghost has a better editor versus wordpress.
- Ghost is really fast. The pages are rendered in just 1-2 sec. Wordpress is heavy so it effects your SERP on search engines. You can configure more settings on wordpress but generally you dont need to customize the seo settings on ghost.
- You are right about the ecosystem. You can struggle with technical or design support issues, but if you use ghost as a blog system, I don’t think you need them much. If you are using ghost for your customer, it is absolutely necessary to change. In this case, I recommend WordPress. :)