It is possible someone seems happy, makes plans, has decent grades, but is actually feeling so much pressure / unease / depression deep inside that they decide to "walk away." We even saw a case here recently, but that young man took his car with him. (Student who disappeared right before a scheduled exam, and LE confirmed later they made contact, and they considered the case resolved.)
However it would still be a very serious concern, for the person's well-being, especially if they don't contact family for a long period of time, IMO.
I honestly do not feel this is a suicide. Yes, it is possible, and most certainly people commit suicide all the time when absolutely no one had any idea they were going through anything prior. That said, I don't believe this is the case and I will tell you why.
1.) Caleb owned and had access to a number of firearms for hunting. I think it much more likely use that method.
2.) Caleb was a planner. We know this. A creature of habit. If he had planned his own death, he would not have done it in such a haphazard way as to be barefoot and have to walk to wherever to do whatever-makes no sense no matter how drunk he was.
3.) He loved his family and his friends. I do not believe he would commit suicide in such a cruel away as to leave without a trace, without a note, without anyone knowing where he went. He was texting to his sister, snapping people, playing with a puppy. Just leave all of those people knowing they would be freaking out trying to find you and may never have a chance for any peace? No. Not Caleb. I don't see that here.
I lean toward nefarious reason here. A drug exchange gone wrong. A hook up that went bad. Someone...perhaps...that didn't like the fact that he hunted and fished? Someone that was jealous?
I have less leaning toward misadventure. My initial thoughts were the water. But he was so well trained and informed on the dangers of the water, there is no way he would risk doing something risky like that even if drunk. Possible, but not likely. Also it would be a LONG walk barefooted to the water and someone would have seen him or a camera would have picked him up. If he did something kooky nearby, they would have found him by now.
I will be completely surprised if he did unalive himself though.
Sadly, however, I do not believe Caleb is with us any longer.