Hm, I can't see how the agreement could be interpreted in any other way, than “sharing the account credentials is allowed only between an under-aged child and their legal guardian”. Though I am of course aware of players interpreting a lot of things from the agreement in any way they want to. xd

Or rather, they don't interpret them at all. ^^;

I also never got the feeling of such a design being there... but well, that's me!
The game is designed to effectively do everything with one character, yet you are able to have up to 16(?) characters on an account. There is absolutely no reason to have that many characters (mules included). With the game being developed as a group effort as opposed to solo, there is no enticement to want to redo missions/quests just to have a separate character. The intent is a family plan. I doubt SE intended a family of 4 living together to have 4 separate accounts.

You want to be able to transfer Content IDs from a PlayOnline account to another?
I don't think I would support that.
Why wouldn't you support that?

Without any changes to billing, it would obviously be a loss of money to the company.
It would have to be changes to billing. There would be enough people participating in it to make up for any production charges.