4 classes are a bit of boring with only 3 lines of skill for each class. What I am suggesting is, we could have a sub class on each character preferably at Vet levels since the difficulty is higher. Having to complete a certain line of quest gives player an option to choose an extra skill line from a particular class. This can make the game very interesting and a much wider range and flexibility of combination of skills.
Also, rather than people have to camp spawns of werewolves or bloodfiends to obtain a specific skill line, it should be presented as a line of quest as in Elderscroll: Skyrim so that the players can skip the part to buy a bite or long camping. I believe dev group has a reason to put it the way it is right now, but the current situation is rather being not very convenient for most of the players.