First of all, please quit using vinegar on your plant. Vinegar is an acid, does nothing to treat insects or diseases, and could damage or possibly kill your plant if used at a high dilution rate.,Before you use any type of natural or purchased chemicals of any kind on your plants it's very important to establish exactly what is causing the plants problems, whether it be insects, disease or just addressing light and water requirements. Second, how often do you fertilize, and how much? Because you seem to be growing the ele ear as a houseplant, there is a distinct probability that you are using too much and too often. Fertilizers used for houseplants should usually be diluted to half strength, and house plants don't usually need to be fertilized more than once a year. I know of many members that have very healthy, large houseplants that receive fertilization once a year.
Any time you change a plants location, the amount of light or it's receiving, you have to realize that it takes time for the plant to adjust to the changes and that issues may arise several weeks to several months after the change in conditions.
As for the position of your plants leaves, it's likely that the particular variety you chose has leaves that naturally hang down like that. Not all elephant ears have upright leaves.
Over all, I think your plant looks very good. Leave it where it is, watch the watering, cut back on the fertilizer, and enjoy your pretty plant!