Seems like because of old age he's probably getting a little confused.. and maybe scared if he's barking at things that aren't there.. but most likely he probably just wants to be around you guys? Why not try moving his bed into your bedroom for a while and see if that helps? Oh and the scratches on the door, if you have any illuminated paper or maybe cardboard (i know it sounds ugly, but it's temporary until you can find something else), you should stick that to the place where he scratches so he won't leave anymore marks..
Good Luck!! Let us know if any suggestions worked!
