Hey thank you so much! I greatly appreciate it, it's one of my favourite and first game I ever played on the PS1! :D
1) That is sort of intended but there is a mechanic for it: when you step over the pitfall on normal/hard, the player will enter this "nearly falling" animation. During this animation if you press forward (or the button towards the hole) then you will get a game over. Instead, when he enters the animation, you should let him pull himself up. He will always succeed pulling himself back to safety unless you press forward during the animation, or he gets attacked/pushed.
I'm sure there are some collision issues as well where some specific pitfalls can be re-triggered twice if you're in the right spot. I'll try to fix those if I encounter any. I'm just so used to the pitfalls that I can run through areas with wooden planks without triggering a pitfall.
2) On normal/hard enemies will recover back up if they're not stomped/finished. If they are downed and you save the game, they are gonna be loaded into the game as "alive&walking with 1 HP" or something like that.
3) SPOILER: The enemies have a 10% chance to travel to other rooms if they cannot find you close by. That also includes the save rooms, most of them are accessible by enemies. There are, however, some doors enemies will never pass through. One of the demo discs for SH1 had a trigger event with a demon child going through the door near the school library.
I'm glad you liked the SH1/SH2 sfx library. :D If you switch to SH2, it changes the loading screen and inventory status. Thank you once again for playing the game and giving feedback! Cheers!