If rust is on the door, then it can be simple to rectify. But if it is within the actual machinery then it could become an urgent issue and need replacing. Luckily, depending on the sort of door it is, and how bad the rust is, you may only need to repair the parts that have been affected.
Scratches and dents can be a big issue on the panels if they are large, causing misshaping. This can stop them from opening safely. If the doors are affected badly they may need an area replaced.
If a panel is damaged, then it can cause more issues to the door, and garage. However, the worst problem for a garage door, is if the actual machinery seizes up, such as the springs, or motor. This would likely need replacing, as this will be dangerous to leave if it’s serious. However sometimes the parts might need repairing if the problem is not too severe.
Whatever the worry, if in doubt get an expert to come and have a look at your automatic garage door in South Devon, and put your mind at rest.