There are plenty of people who are not very good web developers and not even necessarily good web designers, but they’re good at using the tools available to them, and if their design and message are good enough their idea or brand gets picked up spread everywhere.
The main responsibility of strategic planners is to dive into the consumer’s mindset and understand how consumers feel and interact with the brand.
If your blog requires serious interaction with your main website such as blog posts that allow for one-click shopping, then using the same CMS makes integration easier.
If you’ve already created a blog and later launched a website selling a product, it’s might not be necessary to move your blog over, especially if it’s easier to create a blog template that meshes with your main website.
Make good content. Tactics to optimize SEO are so readily available and are built into the major CMSs.
Make good content and the rest will follow.
We can all see when a website is too slow, is intrinsically non-ergonomic, or is sketchy and can’t be trusted.