Okay, great. I'm thinking on the right track here then. I'm mostly after the user's experience here. I want it to be clear they're still dealing with the same site/brand.  I have the same feeling about the 3rd party domain. I just want it all under the same umbrella here as much as I can while being able to keep this fairly easy and low cost.  Thanks for the input. I really appreciate it.

One additional thought... what is the difference in moving it from the shopify provided URL? Should I even move it if I cannot move it to a directory?

Unfortunately, having it on a directory doesn't seem to be possible using Shopify or I'd do it that way. Seems by what you say there is no difference. Once upon a time I had a store on this same site on a subdomain so I'm thinking to just go back to that. My traffic isn't going to be fully dependent on SEO but I'd like to leverage as many avenues as I can in how I go about things.  In terms of SEO, the subdomain would just be on its own separate path, is that it?

I'm planning to set up a subdomain for my Shopify store but I'm not sure if this is the right approach. Should I purchase a separate domain for it? I'm running Wordpress on my website and want to keep it that way. I want to use Shopify for the ecommerce side. I want to link the store from the top nav and of course I'll use CTA's in a variety of ways to point to merchandise and other things on the store side.   Thanks for any help you can offer.