The Colts shouldn't scare any elite teams at this point unless they're bad on both sides of the ball, which would kind of eliminate them from being elite in the first place. If you've got a good D and can hold us like Jacksonville did, you can win even if your offense isn't great. If you've got a good offense and can shoot it out like Kansas City did, you can win even if your defense isn't great.
The Colts D is just non existent now. They may as well keep the defense home, let the opponents run against an empty field, and let the offense go right back out there. Then at least the opponent's D will get tired faster.
It just started. He's coming back. As he's said in the past, he'll continue to play as long as he thinks he's still playing well, and he's still wanted. He thinks he's played as well in the last two years as he ever has, so no quitting now.