I last played the game in June so I may not remember everything but here's what I do remember:

1. None that I recall
2. None
3. Yes but in a medicinal sense (eg. sleeping pills).
4. Minor. There is blood in still images as you do investigate murder scenes but nothing obscenely graphic or animated.
5. Not that I recall
6. Not that I recall
7. Not that I recall
8. Yes, historical (occurred before the story is set and aftermath is discovered) experimentation on dogs. This is condemned by all characters. Nothing graphic however is show. There is also a room with hunting trophies near the begining.
9. Abuse no, violence yes, but in the context of there is a killer in the family that you are trying to uncover. No deaths or corpses shown.
10. Yes, runes, candles, and symbols (incld. pentagrams) are present. Rituals also occurs within the plot.
11. Yes if you count time travel.
12. No jump scares. Tension rises occasionally but I never felt the characters were ever in danger.
13. None the I recall.
14. None that I recall
15. None that I recall. Some dolls are present in the background as set dressing but not used to scare.

All in all I'd say if you're good with a scooby-doo episode then you're good with this, but as the plot is about solving murder it's not completely free of any depictions of harm or violence. Have a look at the images on the store page they give a very good idea of the general tone of the game.
Additionally it's official PEGI rating is 7+ (Fear)

Wow. Thanks!

I've had a grand time playing this game 5 times. Here's what I remember

1. No explicit language
2. No sexual elements or innuendos
3. There are generic bottles of expired medicine in a cabinet. No drug abuse
4. There is dried blood smeared across the crime scenes. These are only in the time travel to the past
5. No lgbtq things
6. No racism or bigotry. John does get teased a little for a spider phobia, but that's it
7. No irl politics
8. Yes. One instance of past animal cruelty. There is a frankendog. It was experimented on, but this is never shown. The image of the dog with all the stitching may be bothersome. This is not condoned by any of the characters.
9. Yes. A woman is murdered. This is the first cutscene at the game. Hardly any animation. We later find out this is how the curse started, he killed his wife.
10. There is supernatural things. Ghosts, a curse, magic mirror, candles. That sort of thing.
11. Yes. Lots of magic. One of the main game mechanics is a medallion that gives you powers. You use those powers as a tool to find everything you need. There is a pentagram at one point, and a summoning ceremony at the end. Time travel via magic as well.
12. YES! There is one single jumpscare! It's towards the beginning of the game. The very first room you can enter, Roger's room. An image of the Hound fills the screen suddenly, and there's a growl sound. It scared the heck out of me every time. This is the only jumpscare
13. No suicide or self harm. In one of the hidden objects games, there is a noose laying down.
14. No mentions of diseases or medical conditions
15. Dolls aren't used in a creepy way. There is a marienet doll you have to find the cross bar things for. And in a hidden object game, there is a voodoo doll. They're not used in disturbing or creepy ways.

Thank you :)