You can use AutoHotKey to make keybinds to delete files.

During the part where you have to collect the mirror shards, there's a silhouette of HER that you can activate, and then she'll chase you. However, you can quickly double-tap E on HER to teleport into the real world, and collect the glass shard, upon which you can just run away.

During the part where you have to collect the lucky tickets, you can make batch scripts to set the time to different things.

During the house part with all the keys, to collect key 8 you don't have to see the key, you only have to be within range to collect it.

To get the peek-a-boo/peek-a-TWO achievement, there is no specific section you have to get it in, so it is perfectly fine to route that in wherever you like.

Running diagonally is the fastest way to move.

The flower in the beginning can be picked up without crouching.

In the piano room, you can sprint for a short while before you have to stop.