French language Q&A Forum

I was always taught (from textbooks, profs, etc) to use "en" with French countries/states/provinces that end in -e or start with a vowel sound and are singular. "Aux" with plural names, and au for the rest--with the exception of Mexique which uses "au" though it ends in -e. Oh, and à with cities. 

Is this "dans le" thing a change in how the language is done or a regional peculiarity or what?

“Nous pensons que c'est une bonne idée.”

Why is ‘que’ used instead of ‘ce que’  if we’re referring to the entire statement ‘c’est une bonne idée’ and not a specific object? 

I’m dying to know why! 

This was the sentence: Vous veniez me voir chaque semaine.

Two of the options for the answer are "You used to come and see me every week." and "You had come to see me every week." 

Same idea with this sentence: Nous allions en Espagne tous les etes. (Sorry, don't know how to get the accents on my keyboard).

Two of the options for the answer are "We used to go to Spain every summer." and "We were going to Spain every summer."

For me, in both situations the two answers mean the same thing and were both correct but I had to pick one. l don't understand how they are different and why one is correct and the other isn't. I'm guessing it's a subtle nuance I'm missing. Can you please explain? Thanks!