Recipe looks solid to me, but why transfer off of the oak? For what it is worth Russian River uses dried sour cherries. You may also want to blend a cup or so of the wine into the beer to boost that character.
I’ve always had trouble adequately souring beers aged in carboys without adding the bugs in primary. I know Russian River does a clean primary, and I’ve never had an issue with this when aging in barrels. Making a starter is a good idea, although if you pitch in primary the wine yeast in the bottle could cause issues for the primary strain (not sure if their “Rockpile” strain makes the kill factor though).