I think Salimbene is right about the possible bad spawns in this case since I've been past Odil's farm many times with no problems. I don't do the Main Quest these days so I can't comment on Oblivion Gates if they have any problems.
This is not specifically regarding WAC, but also any mod that adds creatures and NPC's to the leveled lists and can happen in a vanilla game, but is not so likely. From a lot of the reading I do it's not necessarily the mod that causes it, but the way the game generates cells and which beasts and NPC's it loads from the lists when you are about to enter a cell. If it mis-loads an actor, it's equipment and a lot of other variables, then you will sometimes have a crash which will persist unless you either reload the last save, or wait somewhere, preferably in an interior to allow spawns to reset.
Have you ever visited the Tiber Septim Hotel and found bandits, deer or other actors that shouldn't be there? The hotel is a dumping ground for the game when it has problems loading some cells and their contents, and also is a type of crash prevention. Not that it always works. When I was using OOO I went there once on a vanilla quest and found a Frost Minotaur causing havoc in the main foyer. That was interesting to say the least.
Something many people don't realize is some of these problems can persist in save games and will continue to be a problem. The save game records every tiny thing you do, everything you pick up or discard, quests started and in progress, etc, etc, etc and it also can and often does retain error data. When you get a persistent crash that's always in the same place it's better to not continue with fresh saves until the problem is found and eliminated.
An example of saves retaining bad data is a mod that has accidentally moved a door or other object which has nothing to do with the actual mod, but has edited something in the base game. I helped a friend sort out this very issue with a rotated door and discovered it was a mod that added a sword to the game and a door in the Waterfront had been rotated out of the frame. The thing is the door had no relation to the actual sword or it's location, but in saves made after enabling the mod, the door was always rotated, even after disabling the sword mod. Only loading a save from before adding the mod fixed it. We tried cleaning the mod with TES4Gecko but since it was embedded in the save that didn't work.
I had permanent crashes yesterday when I tried to enter Castle Wolfspike (which I never had before). A bit frustrated I made screenshots of Vacuitys Autumn Leaves for a while, than went back to the castle and the crash was gone.I only met an angry troll jumping around in the castle patio.
Any other mod which changes something in this region?
I don't know where the Castle is but since it's resolved maybe it's also one of those bad spawns. Since you got a trespassing troll, perhaps it was something else previously. Or the troll was really, really angry and didn't ant to let you in.
for doing this.
For the past couple of weeks or so there's been a flock of crows in my real backyard and nesting in the surrounding neighbours trees. Usually it's magpies, but closer to springtime. One bird in particular likes to sit on the fence just out of reach of my dog and it drives her nuts with it's beady black staring eyes. I assume it's the same one. Maybe they have a pact to drive my poor dog crazy one by one. 
.
