Just a little nitpicking about the 10 stars ranking requirement :
Memo Items Found:
20 stars for all 52 memos. You receive 1 star for every 5% of possible memos collected, which roughly equals 1 star for every 2.5 memos.
Nope, you gain 20 stars if you get all the 52 memos, 19 stars if you get 51 memos etc ... if you get less than 33 memos you get 0 stars.
By the way, how do you get a perfect rating, exactly?
It is highly suggested to get all the memos if you aim to get a 10 stars ranking, that way you' re allowed to either save/continue twice with a less than 2 hours playtime or save/continue once with a less than 2 hours and a half playtime (that is if you play in Hard mode and kill 120+ enemies).
I don' t know about you but I' d rather be allowed to save twice than be allowed to skip two memos (I have no problem wrapping the game in less than 2 hours) ...
If you do have trouble to finish the game in less than two hours then here' s a useful piece of advice : pausing the game with the start button pauses the chronometer too, allowing you to read your notes or a speedrun walkthrough to jolt your memory, which prevents you to waste time remembering what to do next.
Here' s a good speedrun : http://www.gamefaqs.com/ps2/919554-silent-hill-4-the-room/faqs/32938
Although you' ll miss a few red memos if you follow it to the letter it gives some very useful tricks to not waste time, especially the trick that allows you to skip half of the Apartment revisited level. Just follow this speedrun without forgetting to get back to your apartment twice per level to see if there' s some new memos in there (at the beginning and at the end of each level), if you see there' s some new memos to take at that precise moment write it down on the walkthrough and you' ll end-up with the perfect speedrun (although if you know the game very well and play really quickly getting back to the apartment twice per level shouldn' t prevent you to finish the game in less than two hours, you have to get back to your apartment both at the beginning and the end of most levels anyway).
Also, don' t forget to pick one sword and one silver bullet to take Andrew' s key, I' m not sure the speedrun writer thought of mentioning that.
Finally, don' t give any weapon to Eileen. Ever. Unless of course you want her to waste time fighting every single enemy she happens to see. Always run rather than fight, unless you come upon nurses , a boss, or the six babyheads pack at the end of the Water Prison revisited level (give a weapon to Eileen to help you fight that six pack, that' s probably the most dangerous room of the entire game). The "kill 120+ enemies" requirement is easily and quickly met killing a bunch of those harmless pipe-like mushroom monsters that are on your path. Fighting any other enemy than those I mentioned would just be a useless waste of both time and health.