if you don't want to re-drywall...
Might try some wall putty if the holes are not too big. Just put some into the holes until it's level with the wall surface. bigger holes would require some type of filler or backing.
Road bikes are a lot more efficent and you can go a lot further without getting tired.
I boguht a used Trek for about $200 and upgraded the tires. It's pretty fast...can get up to like 25-28 in the flats with little effort.
Because of the high pressure tires, the road bikes don't take bumps...