If you have to make a choice, I would pass on the Caudalie set. I usually love skincare, but the Sorbet in the set made me break out. Is definitely a one-off because other products from the brand work fine, but I just can't recommend that Sorbet.
Regarding doubling down on the gifts, I believe the new "rewards bazaar" makes that impossible, because it only offers you items that you are qualified for. So, if you have the gift in your cart, and redeem in store, it will give you an error message when you return to your cart, because the gift is no longer valid.
Hope that makes sense!