A fair amount just doesn't seem to do anything.
A big issue is that you can't tell how much time you have left at any time other than when you're traveling. Like how much travel time verses how much time left before you fail. Kinda important for knowing what to spend your time on at any site.
Choose gun and lamp.
Always fix the bridge unless you don't have the time.
Bible doesn't seem to do anything. Don't take gamblers bet.
If you find broken door house ignore it unless you got party needs to take care of. If you got lamp and gun you can look in, see the bear and kill it with gun. Though minor stuff can happen this way your party doesn't freeze or whatever since after killing the bear you can eat/rest etc.
Always light a fire before sleeping 6 hours if you got a sleeping bag. Though there are a few times you can get that option even if you didn't select sleeping bag and exhaustion isn't much of a thing to worry about in game
Don't investigate stuff, just bodies, bones and trauma. I don't get the doppleganger event, doesn't seem to do anything.
Eat when your party is starving and rest by the fire when your party is cold. Hot meals also help mood.
If you mind your parties conditions and remember time left from when you were traveling it is easy to to win/stop the outbreak. I only lose party members when they randomly catch and die from dysentery. Not sure what effect being bruised or stress does to you even.
You will always have two members fall in love and there is no reason to say no, it just makes them upset at you, which granted doesn't seem to do anything.