There was enough evidence to pretty clearly resolve almost all parts of the story with little doubt outside the context of the story. It is clearly confirmed by the story and your conversation with Delilah that the girls were the ones that trashed your tower because you find your own bed sheets that were stolen from your tower in the girls' camp.

It could have also been the hermit guy who did it. I'm going with thinking it was probably a bear that trashed the girls' camp. Or maybe he just wanted to kill you, but he left without ensuring you were dead. He had motive to keep his research hidden from you. He probably wanted to scare you off so you wouldn't keep investigating, or maybe he hoped you would wake up from the head trauma thinking you dreamed it after hitting your head on a rock. Ned hit you in the head because he saw you just found his clipboard and started freaking out with Delilah about him being monitored. I think the fact that you could see Delilah's tower from there was a mistake by the environment artists. It also could have been built away from the view of the watch towers because it is in some way secret research and the university and the government wanted to avoid prying eyes, as mentioned by the signs around there. It's also possible he was involved in the project with the university and he oversaw its construction to hide it in that valley. The response above be does a good job explaining the site. Not the longest story, but certainly fun and it didn't feel short when I played it from start to finish today. I got 5.5 hours out of at a more leisurely completionist pace but I thought it was a good length for its price and especially for its content.

I guess if you thought of the player's thought process as like Fox News, and Delilah's logical thought process as like CNN, then yeah the game has perfect logic. So their totally BS panic freakout and paranoia when you're reporting to Delilah what you find out there is joke. and had perfect line of sight of the place. The only BS being that Delilah should've known what Wapiti station was and who was using it given she'd been doing the job for 10 yrs. But yeah at least they did reasonably explain Wapiti Station & Ned. The entire story is still BS despite this regarding your other questions. You find this out when you go into his house on that little rock hill through the hatch at the end. Ned obviously just broke in and placed those test reports to make it look like something bigger because he's a nutjob & stole some equipment from their camp. The notes left throughout the game clearly point to that the Wapiti station is actually a University run science research station they've setup for a while and only use at a particular time of the year (think geology / atmospheric sciences). But to answer the wapiti station one is pretty easy:

Firewatch game wapiti station