Having been on a low carb diet for the better part of 2 years now, I question the conventional wisdom of needing carbs for energy. Fat is a much more dense source of energy.

I have never experienced an issue with running out of energy, and it is just not a problem for the majority of the millions of people who are low carbing it.

Me, I would go for the PB. I don't think PB causes thirst though. It may cause some dry mouth because of the nature of the food which might lead to a desire to drink.

I suspect the reason the peanut oil is replaced with some other oil is that peanut oil is valuable.

It is true that carbohydrates contain a small amount of water (that is what the hydrate part means) but the amount is small enough that it probably does not make all that much difference.