Is the 14.8% with the bourbon or without? Not too many yeasts will eat their way that high. Which yeast are you using? I'd go higher on the IBUs, they fade over the time you'll age this. Yes to adding the sugar 3-4 days later. I would drop the c-60 quite a bit, and maybe use D-180 Candi Syrup to replace some of the brown sugar. You'll still have some of the same flavors, but without the cloying sweetness your faded IBUs won't be able to balance.
If you are going to ferment this as 2 5.5G batches, I'd make them 2 very different batches. 2 yeasts, brown vs D-180, dry-hopping, 2 different types of wood cubes, bourbon vs rum, etc...
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