A: If the damage is repairable then it is definitely cheaper and better to mend it. But if the damage is major, then getting a new appliance is a better option.
A: You can place it against the wall but before that, check if it has a metal grid at the back side. If it has one, then keep a distance of at least an inch from the wall.
A: Softener sheets make the clothes soft, but they also block lint filters in your dryers. If you prefer to use them, make sure you clean the filter after use.