The easiy way to find method and offsets in an unity games is to dump the game and search in the dump.cs file. Watch how to dump. For non unity or undumpable games you have to open the code compiled file into a disassembler and find functions and offsets.
No, voidHook can be used to hook non void function too. However the return value will be ignored.
Game guardian doesnt allow us to force call a function. Update methods are methods in unity games that are called each frame. Since update methods are called many times in a second we modify update method to also call other methods.
Yes you can. voidHook function modifies the target function to call destination offset without overriding the target function. The target function can be any function.
Yes you can.
Yes offsets are different in 32 bit and 64 version of same game.