How might I use a skybox with the BEE2 mod? Also, how do I make floating catwalks not connected to a wall or floor? Thanks!

It depends on what version of BEE2 you're referring to. If you use BEE2.2 (old version), you need to use the Skybox and Skybox Wall items. I'm not exactly sure how those work. BEE2.2 catwalks always need to be fully attached to a surface. If you are using BEE2.4 (newer version), there's no way as of currently to show the skybox within chambers, but it's been suggested several times and will probably be implemented in the near future. Catwalks work differently in BEE2.4, meaning only the corners and ends need to be attached to a surface. See the item description for more info on that.

Also, how do the BEE2 VacTubes work? I cannot get them to turn.

Stop commenting that on every post, it's kinda spam...

It is actual spam, with a hidden spam link. Their posts have been reported yesterday already :/