Last time I looked into forcing high values, it was randomly working with some items. Wood used to work.
I used to buy a stack of 700, restart the game, group search for it and the value after that, and force changing both quantity and verification values to 500M ticking add to value, do not replace.
I'm not sure if this still works, I'll get to it later. Once you have one address working, just spread its quantity pointer around.
Good luck.
Old video:
1. This is the most detailed pointer tutorial I've made, listen to the voice over, I'm explaining what to look for.
2&3. First you have to understand what kind of info you are dealing with and how it is used, the logic behind the process. There are many factors to consider. Usually you're searching for quantities of a stack or the value of an IAP. Next to this information you will find similar information. If you're looking for a quantity value in your inventory, once you find it, scroll up and down the address list and you will find the quantities and other properties of the other items also in your inventory.
Pointers are like folder paths in your computer. When you copy a purple address (one that has another address being pointed to) and search for it, it is a similar action to the "folder up" or "go back". When you long press that address and choose 'go to pointer', it's the equivalent of opening a folder, going deeper into the directory. This is merely an analogy. Then you look up these purple addresses and look around them and sometimes there's useful information. Once the item ID is found, you can copy the address managing this "folder" (the pointer) and paste it in some other place. The same goes for quantity pointers. Thus the guides on how to put stuff in your inbox and duping equips through a stack of wood in your inventory.
Cheers