Two different suggestions here.

Number one:

Date and time of the initial post of the thread in the forums. Presently, this is only implemented for the last post of a thread, and it happens, that, because threads are sorted by the time of creaton of the last post, the thread's information is not neccessarily up to date, and it appears on the top of the list only because someone has decided to "ressurect the thread from the dead", if I may say so.

Number two:

A limit of what can be done with one animal's energy. Now it is possible to use the whole energy bar in three hours of questing or in ten (or tens) of days of crafting, while questing can be just as hard and demanding as crafting. So if you set an animal to craft something for next three days, there would be a message appearing: "This cannot be done. Your animal only has energy for so many hours of crafting/training." This could also implement the suggestion as stated here: http://beastkeeper.com/thread/9045 , because just like we can craft four sticks in sixteen hours, we can train an animal for the next three or four levels continuously.   

I like your first suggestion but not the second.

I think the increased energy efficency of crafting multiple items at once is perfectly balenced by having to wait the entire crafting time to get the items.

I agree with Lytala; you voiced my thoughts.

If pets are meant to represent animals, then I would assume their energy is spent by doing whatever they have to do, and then regenerated by resting, in other words, doing nothing. For a pet, I see no trouble in having to walk/run/fly, or craft, or train, two hours in a row. But doing it for three days without a single moment of a rest is fatal, just as unlikely it is for players to be able to play Beastkeeper for three days without any rest. That is the kind of a limit I was thinking about.