Just want to give this post a bump since I have the same question. I am a totally new WordPress user and am trying out the SG-Double theme as well.
I am hoping to tinker around with the style.css spreadsheet (making some minor changes like page margins, colors here and there, etc). Don’t worry I won’t make any changes yet!! But…if I did make any changes, will this basically ruin everyone’s SG Double site? Do we need to make a child theme of this child theme?
thank you,
Jeff