I have heard the gurgling sounds from my bunny rabbits stomach before and there was no issue. Sometimes if they haven't eaten enough fiber, their stomach makes weird noises. Rabbits don't overeat. They only eat what they need to and once they are full, they will stop. So it's unusual to see a rabbit eating more than normal. What type of food are you feeding it? If it's food full of fruit and seeds then expect your rabbit to overindulge because they love this. If it's a high fiber pellet, then a little bit will fill them up a lot quicker. If your rabbit swallowed something, the vet should have done an x-ray or a physical exam just to give you peace of mind. But if your rabbit is not having issues now when it's eating, then it could be resolved.
Regarding the urine issue, if your rabbit is six to eight months, then the smell and frequency of their urine can be related to them becoming mature and entering adulthood. But also some food does cause the urine to smell or change color depending on how much of it they eat. But if you think there is an issue with your rabbit, then do go to another veterinarian who has experience with rabbits for a second opinion.