Question after a 2nd (less overwhelming) play

Other Games Galactic Strike Force
1

I received GSF from Kickstarter months ago and played it immediately with my wife. We were both a little overwhelmed by the amount of cards (and text on cards) that we had to keep track of. Due to this (and getting distracted by other games and work and such), I didn't get back to it until today.

I have one question though on a rule I believe I played wrong the first time.

When the game begins, there are 45 Station deck cards in play (5 cards x 3 stations x 3 sectors). As you buy and use these cards (or they get flipped during Aftermath) slowly you build up the Station Card trash. When a Station deck runs out, you refill it from the trash (not the deck, like we did the first game), correct? So for the most part, there will just be those same 45 cards floating around the whole game, right?

Is there ever a time when you do use the Station Deck? 

2

The station deck is the station trash for this game as well.  So you don't just use the 45 station deck cards.  Once you deal the original station cards out, the deck becomes the trash and is the place you will discard to, with all those remaining cards waiting to be cycled into the game.

3

When a station card is scrapped, does it go to the top or the bottom of the scrap pile? The rules clearly state the bottom for Mission cards and Opposition cards, but they are ambiguous for the station cards.

4

With the station cards it doesn't matter too much because you're going to shuffle that deck before you redistribute the station cards.