Would this product hold up in an aquarium?
It probably would since it is resin based.
If your tank is big enough, it could work. However, I don't believe it is made to be submerged in water, especially salt water. The paint may erode therefore releasing harmful chemicals that could be detrimental to your wildlife.
That's a tough question honestly. It is a well built statue and made of porcelain or some material of that sort. The statue from what I have seen would have nothing to suggest it would fall apart in water other than the Felt bottom to keep it from sliding. That is easily removed though. I would expect maybe a little color loss over a long period of time, but most aquarium items do. I would say go for it as its a decent price and well built, and looks good. You can go to pet smart and get a cheap on that looks terrible for about the same price and half the size.