So- you are asking when to use 'when' in a sentence. When you are asking how to use when in a question, you are already using when in a sentence, because a question actually is a sentence. I like to use when in a sentence whenever I like.
You cannot end a sentence with because, because because is a preposition.
I gradually did not understand your question because you did not give "the sentence" that you're asking how to use it in.
Obviously you can because you just did.
He kissed her because she was under the mistletoe.
You cannot ordinarily use because three times in a sentence because because is a conjunction.He was finally elected not because of his party, or because of his charm, but because he was the better candidate.(see related question)
yes because for example sentence she was diffident about her opinion
No, because it is not a real word.
Because of your lasciviousness you are in trouble
yes because its nice
I skid because of the ice
No, because it is never good to start a sentence with the word "but".