Do you have Adobe CC? If so why not just edit in Pr with the r3ds and skip transcoding.
FCP7 and Color is a bit creaky but you can also do a relink to the r3ds from the FCP export. Bit laborious.
Main thing is maintaining file names and timecode/reels to locate back to the r3ds for any future 2k versioning. Make xmls as well as EDLs regardless. FCP7 can do it but there are better options. You could even edit in Resolve.
I was wondering why a 5 year old application, discontinued 4 years ago...would be the best choice for this.
Personally I'd do it in Avid and go to Resolve for final grading. But that's me. Premiere Pro CC can do that too....and no transcoding. BUT ONLY if your machine has FAST FAST processors, GOBS of RAM, a GPU card to enable CUDA...and a fast RAID. Avid does this without those resources needed...by making the footage more manageable to edit.