Hey guys,
i'm wondering about the max FOV number because i'm afraid if i put a higher than allowed value i get banned

everything up to 80 is allowed. I am using 70

If you use cl_fov comand you can put 80 with no problem. If you use some Cvar tool who give you vertical option use at maximum a value of 79 becouse 80 or more have a bug on some machine and you can be banned. On my pc i use Baldur Cvar and when i put vertical fov 80 i get a speed+jump increase more that normal (not the feel of speed , my friends say look like a speed/jump hack) so be carefull. Make some test with a friend to find the best for you , at least i did like that.