Some tips:
"quiz, photo and tips" file in the translated download is wrong in places for the bundled version 1.0.
Trap quizzes:
Trap #2's "located in Osaka" question answer is Tsutenkaku. Tokyo Skytree isn't right.
Reign name for 1989: Showa (I think, otherwise try Heisei)
The sweetest fish answer: monkfish (red bean paste? I don't get it).
Poison's SFV arcade edition art: Love Hurricane
Trap #6, release date of PS: December 3 ,1994
Trap #7, home appliance with sweets: Humidifier
Bridget leaves if you go into their bathroom.
If you go to Straddle House, top right in the ninja village, you can loot the guy's chest at the top left twice. Do it once before fighting the rats and again after.
If you go all the way to the west (right) side of the island, you can follow the coast down to the oasis, and then to the cave where you can fight Chicken Guy for 100 yen each time, and you can also fall down the hole at the top of the maze. I think you will get stuck if you try to visit the lower level more than once, since you need to take the boat to get to the exit, and the boat won't return if you go there again. The lower exit takes you to the north east corner of the map for no obvious reason.
After you visit all the easy-to-find characters, the bundled hint pictures are helpful. Visit the Oasis and look for the shady old lady near the sign to start. Ignore her hint, the Tsubasa ticket is in the well to the left, next to Maria. Another secret ticket is below the fire extinguisher at the end of the left hallway, boy's school first floor.
Mystery: If you look southeast of the City (tile with colorful houses on it from the island map), you will see two pine trees and a slightly yellow-green round tree between them. Go there and Use it. It mentions Tadano Memo Yoshi. I don't know what this does.
Places not to visit: The final spirit in the recollection room (shows ending credits), and the stairs past the priest, leading under the church...
Other thoughts:
The automatic translation isn't great, with lines running out of the message window. Gaiseidou has been working a long time and hasn't changed their art at all. The island feels too much like the island from the last game, IMO. Also there's a lot of talk about underage kids and butt hurting.