Use of Dreamweaver is Still here. It's not going anywhere for a while as I'm still using it everyday and it's still a necessity for basics, static, and some dynamic sites.
Anyways going by the list you have now, (always prepare for growth) If I was you, I would hire a designer to take care of the design and implementing processes. The easiest is of course what others have said and fastest unless you want a very unique design. Use CMS. CMS is nice, but the templates used are bland in my opinion, and each template has their own pros and cons due to the designers'.
Everybody has their opinions about CMS, what's available but for the most part they do the same things. Each with their pros and cons so you may want to look into them. But it will also require the designer to have knowledge of what you're thinking of using as well.
Anyways, CMS will take care of your social media, user accounts and so on with plugins or what not. But you're also talking about an E-commerce store, so what kohoutek said is also a very good option (specializing). Cause you will need a store database integraded. Included customer support tickets and etc.
You won't really need a developer unless you need something unique and not available anywhere else. And for the most part... it's mostly been done somewhere before, and sometimes available for use.