I was wondering if it's allowed to set the recipe book up before you move/start the timer?

so the supposed rule is that timing starts 1 second after world load unless u had a first input during the time frame.

The only thing you are allowed to do before timing starts is change difficulty and check f5 mode. This is because you can load a world with in f5 mode if you exited your last world in f5.

Opening your inventory is considered as an input so for this reason the timer will start if you open your inventory (set the recipe book)

Also following what Pooply said, it really only takes like a split second to open it so it really doesn't make a difference.