Always return the free gift. Majority of fragrance retailers want their free gifts back so that the next person who would like to buy could have it. But sometimes a retailer would let u keep it. So I would say, always take it back and if they let you keep it great.
I think the right thing would be to return it. I mean it is supposed to be a free gift WITH purchase, and if you're not keeping the item it seems a little wrong....nothing to lose sleep over, but I wouldn't feel comfortable keeping it.
It depends on the company's policy. I would personally return the item, but it also depends on the reasoning for your return. For example, if it is the company's fault, I think it would be okay to keep the item...the company may even offer you the item for your inconvenience (a nice benefit)! But, my best advise is to check with the company when you return the item.
I didn't notice any dry-down. To be quite frank it was too over-bearing for me I like He Wood Ocean Wet Wood much more and it's 1/4 of the price tag.