For the stone Tablet, you must find a rectangular stone. Flip and it should look a bit like a Yoshi. Run around it (in 3-D) once. The stone Tablet should appear on 'Yoshis' head.
For the water Tablet, go to the start of the chapter(5-2). keep going right until you reach some water. Sink to the bottom-don't worry, you won't die-and if you can't see a chest then flip, and open it. The water Tablet should be inside.
For the fire Tablet you must find a place where there is a Crysra (I think it's Purple). If you flip you should see tons of ? blocks(Hit them if you want to). Then in 3-D go left(there should be a path to follow). Once you reach the end of the path flip back into 2-D. Go right until you see an unlit fire. Switch to Bowser and light it. Then you will see the fire Tablet.
Hope this helps!
Go to the very top of the highest rock (the one with all the blocks going all the way to the top). Use tippi and you will see a hidden box. When you just to hit it a ladder will pop out. All the way at the top there are stone walls. Put them into the wall in this order: rock, water, fire.
You must find Merlee in the ladies bathroom.
Chapter 4.
It's Chapter 1.
It's in Chapter 7.
Chapter 1-1
You will "find" him after chapter 6.
By getting dottie
Easy just ride the boat
It is 5963
go to bestouvise in chapter 1-1
It is 5963
in chapter 7-1
As sap soup is only available in Super Paper Mario, you get it sometimes when you defeat Floro Sapiens in chapter 5.