tyrannosaur family values

The more that I've read about the tyrannosaur growth rates, the more problems I've seen. First of all, the paper places the age of senescence and death at about 30 years old. That is really young for a big animal. In mammals and reptiles, the larger and animal is, generally the longer that it lives. Also, the paper said that T. rex and other members of the group would have only spent about 30% of their lives at their adult size, which seems to me to be extraordonarily short. It does mean that more of their lives would have been spent being able to run very fast, thereby benefiting their hunting ability, but only having 10 years to reproduce and raise a family presents a problem. The biggest problem lies in when tyrannosaurs would have reached sexual maturity relative to somatic maturity. If they are both at the same time, then the females would be starting their own family group well after loosing the ability to run quickly. Does this mean that females did not leave the family group they started life in before starting their own family? For a youngster to be helpful in the hunt, it would have needed to be at least 2 years old (youngest tyrannosaur individual found in association with larger individuals) and would have only weighed about 50 kg. Would aunts and even uncles have helped to care for the young for 2 years or more? possibly sacrificing their own reproductive success?
This also means that the mother of the family group would have died well before any of her offspring would have started reproducing. Thus a family group would be siblings from possibly several broods (therefore half siblings- usually reducing it's willingness to help with sibling's young compared to starting its own family group). In the case of Sue, the most famous T. rex, Duffy, a jouvenille found in association might have actually been her sibling rather than her offspring.
Sue presents another problem. She is really, really battle worn. Evidence of broken bones, infections, torn ligaments etc. This degree of wear and tear initially lead Peter Larson to believe that she was about three times older than the newest age estamate of death. If even a few of those injuries were sustained during the period when she was experiencing exponential growth (up to about 2.8 kg per day) then she would have needed not only to be cared for by her siblings, but massive quantities of food would have had to been draged to her in order to sustain her increadable growth spirt. Also, that much injury in 30 years seems a bit excessive. Have young tyrannosaurs been found with proportionate amounts of battle damage? Would childhood injuries be as visible as those seen on Sue? And what about the Gorgosaurus at the Indianapolis childrens museum with what apears to be a tumor in its brain case? Could a cancer have sprouted up and grown that large in the last 10 years of its life between reaching maturity and death?
I'll include some other problems and implications that I've noticed in another blog, but i've notice that this one has dragged on a bit long.