That MBP is fine for running CS. I have one from early 2013 with 16gig and I run CC and FCPX/Motion on it with no problem. I use a Thunderbolt display and external TB SSD drives as well as a 4TB RAID. I have the 500 gig hard drive and there’s almost 250gig free after all these months. That 768gig drive is pricey and if you’re primarily talking about editing then you’re not going to be serving footage off of it so you might save some dollars there.
I picked up a new iMac just this week (27″, i7, 24gig RAM) and editing on my MBP now feels like a chore sometimes. All this after 4 days!
So why not CC? There really is a difference.