Unrestricted sharing of free* items from iTunes Store

Question

We are trying to find a legal but convenient way of managing our family iTunes purchases and sharing.
We are just beginning to use iTunes on a couple of new Macs, three iPads or iPod Touch devices and two old PC's.
We have a home Wi-Fi network with a network drive, where we can store items to be shared.
The children in a few years will move out and will take their music, e-books, etc. with them.
Our Internet connection is slow we would like to avoid downloading the same free item from the iTunes Store to libraries associated with different Apple ID's.
We want everybody to eventually have his/her own copy of our home videos and voice memos recorded on portable devices, which can be further shared without any restrictions.
I understand that some of the rules that Apple set for iTunes users are as follows.
1. Every item purchased from iTunes Store is marked with the ownership information i.e. information about of the account it was purchased from. (The account is identified at any given time by a unique Apple ID.)
2. The ownership information on an item can not be changed, i.e. I cannot give an item to somebody else, declining to use it any more, and transferring the item to that person's iTunes library associated with that person's iTunes account.
Question 1: Are the statements 1 and 2 above correct and precise?
Question 2: Does the same apply to free items (iTunes U, e-books, iPod/iPad apps) from the iTunes store? (it is painful to download the same free item to different accounts over a slow Internet connection.)
Question 3. Does the same apply to music imported into iTunes from a CD?
Question 4: Is it true that in order to allow the kids to take their items with them when they move out, one has to make sure that the items
have been purchased from iTunes accounts associated with their own Apple ID's and placed in their separate iTunes libraries?
Question 5: If I add our home videos and voice memos to my iTunes Library associated with my iTunes account, and do not retain other copies, will it be possible to copy such items to libraries associated with other Apple ID's without any restrictions? Will it be possible to extract such items from iTunes?
Question 6: As long as we are using the same Wi-Fi, can we share music, video,  ebooks from libraries associated with different Apple ID's? I believe so, but please confirm. What are the restrictions? Is it helpful to place an iTunes library on a network drive?
Question 7: I believe the same iTunes library can contain items purchased through different iTunes accounts; also there can be multiple iTunes libraries associated with the same iTunes account. Are such options useful and would they help in managing family purchases and sharing?
Question 8. I noticed that a portable device can sync (download) items from only one library. Different persons have apps and music from different libraries associated with their own Apple ID's. We would like them to have also on their portable devices the same free e-books and home videos or voice memos. Do we have to copy such free e-books and voice memos to all the different libraries?
These must be questions many familes ask, but I could not find a precise and comprehensive answer despite browsing the web for several days.
Could you please help?

Answer 1

No. It said nothing about authorizing a computer. I only have one I-Pod and one computer with my library on it. I have listened to these 4 songs for over one year on my p/c and I-Pod. This is a new one to me. These 4 songs still show up in my "purchased" section of my I-tunes but I cannot play them and they will not
copy to my I-Pod. I see where I can repurchase these songs at the I-tunes store, but don't want to pay for them twice. What do you think is going on? Thanks.