Regarding breed and temperament:

I am fairly new to beef cattle myself, although I did grow up with them.  However, I am convinced that temperament has more to do with bloodlines and perhaps the way the animal has been handled in the past, rather than breed.  I have a herd of red angus, all of which have been brought in over the past couple of years from two other herds.  One set are docile and reasonably trustworthy, even with newborn calves.  The cows from the other herd would, as often as not, run me down with smiles on their faces.  In fact, I had one take a run at me this evening.  They are all as docile as can be during the year, but once they calve, it's like my herd has a split personality.

That's my experience (limited), but your mileage may vary.