[Closed] 2 hopefully quick questions

Hi everyone,
Got 2 questions here:

1. how do I create an object (like a box) in memory only? I don’t want to see anything in the viewports, I just want to create a node that I can use as a starting point to create other instances of that object.

2. seems like it should be simple, but for whatever reason I am having a hard time with this. I have an array of boxes, say 3×6 all with 1″ between. (it could be anything really) I want to rotate the whole group about the centerpoint of the group. BUT, this group is dynamic… other parts of my script can change the size and number of objects at any time, so I was wanting to avoid selecting the whole group or otherwise treating them as a group. I was thinking more like each object gets rotated about a predefined matrix… am I overlooking the obvious??

Thanks,