Okay, I can try to answer these
I have bad understood about what interrupts are (En Français, "interrupteurs" ??), it allows the prog to execute 2 code parts at the same time ?
Interrupts do not work well in Grammer, but for some short pieces of code they will work. They let you run a subroutine automatically several times per second. This feature is not finished and will change in the future. (In fact, I am going to try to change it today to make programs run a tiny bit faster and have extremely good control of the interrupts).
And I don't understand too what you mean by "*By adding 8 to the Method, the data will be read as hexadecimal". Is there another mean to code sprites than hexadecimal ?
There are two ways to store sprite data. One is by making pure data, and the other is by using hexadecimal. Using hexadecimal is easier, but the data is twice as big. Thank of it like taking a hexcode and using AsmComp(. Also, using hexadecimal code requires Grammer to convert the data before drawing it.
I have made a few sprite editors to help making sprite data easier.