Name of God in Judaism

Hello all,

I’ve been learning more about Judaism recently, and I’d like to ask about the name of God.

I understand that the tetragrammaton is not used and the term Adonai or HaShem is used instead.

1. Is there any written scripture that forbids using the term, or if it is due to the holiness/respect of the term?

   1.1. Given that the concept of afterlife and hell is very little in Judaism, for those who say the term, if it is considered a sin, will they be punished? (This question is coming strictly from a Christian/Muslim perspective)

   1.2. Given that Judaism is an ethnic religi on, and as far as I understand, it does not concern what outsiders do (Ie. Non Jews), if others use the term, are they punished by God?

2. Does the Term “El” or “Elyon” have the same significance as the Tetragrammaton? Is it considered a sin/disrespect to use this term? Does it refer to the same god?

3. Given the tetragrammaton is not used, how is God referred to in the Tanakh? If not by the tetragrammaton, how is the term not forgotten if it hasn’t been written in the scriptures?

Thank you.