flaked oats in a barleywine?

If you want to add body, mouthfeel, silky/creaminess and smooth it out a bit, go for it.

It will add very little flavor/aroma contributions to the finished beer. You'd need to use around 10% or much more Flaked Oats to get any "Oaty" flavors, and they will be subtle- likely lost in the other specialty grains/flavors.

If you add more than 10% (Even with flaked) you may want to consider doing a temp rest at 104-122 for 30 minutes for a beta-glucan rest. You don't want a stuck sparge. Flaked oats don't normally need a temp rest if using under 10%, but if you are around 20-30% flaked oats in your grain bill I would do one just to be safe, stuck sparges suck.

What do you desire/hope to get from adding flaked oats to the beer?

 

Infection in the wood can be avoided by boiling the wood in water. I boil for 5 minutes. Spirt soaking may or may not kill all bacteria. I am not sure what percentage of alcohol is required to a total kill, so , perhaps boil first, then soak spirals in rum.

Never heard oats in barley wine, but that don't mean it will be bad

 

I think it's more of a matter of the oats being overpowered by the other specialty malts in most cases.

 

Another thing to consider is if you have concerns about the rum soaked spirals and think you need something to counter act their effect, don't put then in. Is it the rum, the oak, or the combined effect?

 

Just simmer the oak spirals in water for 15 minutes and discard the tannin rich leftovers. Then soak in rum.

Add the oats near 10%, it will add mouthfeel, silkiness.creaminess and smooth it out.

Let us know how it turns out.