Don't max beckon. 4-5 is plenty. Use the rest for hellscream/crushing blow/slashes
Don't worry about gear until 56-60. then buy a str glyph set. Very affordable, and will take care of your mana regen and health. Use the required amount of str for that set, and put the rest to dex.
While leveling with a party, do not be a scatter bear. Use your skills wisely. Bears are to tank and crowd control. Find the nearest wall/corner within range of a mob. Then beckon to pull them to the wall and group them together, run around and stomp them to the wall. Repeat until they are dead. The dps classes should take care of the damage. You just need to live, use taunt to pull the aggro, and keep them on you.