LurkerNoMore

Hello, I've been lurking on this forum for over 2 years but decided to become a member today because I wanted to ask you guys some questions about Lego Dimensions. Initially I was going to get the Back to the Future and Portal Level packs to add The hoverboard, companion cube and the two minifigures to my collection and sell everything else on ebay. However after seeing year 2 have I just ordered the Starter pack along with The Simpsons, Back to the Future and Portal 2 level packs and the Stay Puft Fun pack. I would still like to sell the pits I don't want but before doing so hope some of you can answer some questions I have: - If I sell the Portal 2 sentry turret and companion cube parts/bases is it possible to finish the level that comes with the pack? - What unlocks the level in the game? Do any of the three bases unlock it? Just the character base? All three bases? - If I sell the Ghostbusters Terror Dog and its base will the buyer be able to play the Hubworld? The game should arrive this week and I'd like to thank you in advance for your help :)