Subdomain Question?

[The_big_fella]

Hi, I've had a website at www.mydomain.com. I then set up a subdomain shop.mydomain.com to install and test OSC. Now that I have everything set up and the shop is ready to go live, is there any harm, from an SEO perspective, in leaving my shop at shop.mydomain.com and just redirecting www.mydomain.com to there?

 

Also... I've installed the Dynamic Meta Tags contrib and the Ultimate SEO contrib and wast just wondering, as I'm a noob to this, are there any other essential SEO contribs I should be getting.

 

Any advice is very much appreciated!