No one really knows what the fuck each stat is supposed to do, but with 5 on everything you're pretty much unbeatable.
Int - combat arrow moves slower. At 10 it's much slower so easier to get a hit or a crit.
Dex - increases size of "crit" area, making crit easier to hit.
Str - increases size of non-crit area, making non-crit easier to hit.
(with Int/Dex 5 I crit often, then I work int to 10 to have a stable combat speed for most of the game)
What I would add to your notes (which are all very good).
To unlock everything in the gallery, you need to get "sex hit" by every enemy. Not an issue except for two.
For the clogged toilet, you only get that fight once. Stall/miss until you get a sex hit to get that image.
For Sucky, you need to miss at least once on the "finding the doll that is the alive one" once to get that image.
Those two can be missed if you're not careful and unachievable without a new game/load otherwise.