1) Early on in this story, Dioneo tells the group gathered around him that the Marquis of Saluzzo, Gualtieri, did not wish to take a wife and implied that he was wise for this. It became unfathomable for his followers however to accept this, so at their behest he chose to take a wife of humble upbringing from a neighboring village. This led me to believe that Gualtieri did not have high regard for a woman of the more noble class in his village. After marriage his wife, Griselda, is put through a very difficult time by Gualtieri for a period of some twelve years. Gualtieri had long since given away their two children, and his horrific treatment of Griselda had finally reached the culminating point when he said he planned to divorce her and marry another woman more comparable in stature to himself. Griselda never wavered or showed and visible signs of scorn toward Gualtieri, and accepted whatever he told her or decided on her behalf. In the end, Griselda was in fact being tested by Gualtieri to see if she had what was needed to make him happy. What Gualtieri feared was losing his tranquility which he enjoyed before he was married once he had taken a wife. Griselda showed him however that she was not troublesome in any way for him and would do whatever he asked without bringing on any underlying scandals. In the end, this is what Gualtieri wanted, and he chose to show his people this example as a way for them to look to when choosing a wife.
2) All I know for sure in comparing the frame tales from The Thousand and One Nights and the Decameron is that the stories are all rather diverse, but seem to all have a quality of being able to “pull” the reader (or listener)in. Also in common is a need in both of these overall stories for the fictional character that tells each of the frame stories to pass time by telling them. Beyond this, I do not really see a real way of “connecting the dots,” so to speak, in the tales which are told and those that tell them. But for the ascribed purposes I have already mentioned, the stories accomplish their goals without question in my opinion.
3) The nightingale is clearly a symbol of the heart, and in the case of Laustic it represents all that can be obtained by the second knight from his neighbors wife whom he loved, but could no longer stay in touch with. Since this was all that he could keep of her, he put it in a sealed casket and carried it around with him everywhere. Prior to his receiving the nightingale from the neighbors wife, the nightingale was killed by the husband of the wife and thrown at her chest. This left blood, and it is symbolic of her broken heart.