OOh, meant to mention one other visual principle you may not be aware of. It's called "Shrinkability." Meaning, whatever text or graphic elements are present in your logo at large sizes needs to be readable/not lose detail when shrunk down.
I noticed you mentioned you'd be using this design/icon in social media. Don't know if you intend on using the tag line, but...well, if you can't read something without squinting at this size on the screen, it'll be nearly impossible when made smaller for handheld devices (iphones, etc.). Hope you don't mind I'm speaking about these things to you, but I feel its necessary for every client to know, especially clients who are using their designs across platforms. Even on a business card, when your logo is shrunk down...or on an envelope, or on a pencil....that sort of thing even encompasses social media applications. :)
Have a good one! -Jennifer1