Roar of Sacrifice for Marksman is already a problem if they are taking pets away for that spec. Not worthy to rework if there is no pet available to begin with, probably best to just take that spell away altogether.
Beast Mastery seems like an upgrade here, but even Survival has a pet (the least pet compatible spec has a pet?), so it doesn't make sense to take a key function away from Marksman... It makes me think that the goal is to marry Rogue with Hunter?
I think if Blizzard made a fourth spec for all classes, then the game itself would get a bit more popularity... Leave the original classes/specs alone, they work, instead bring something new-new to the table, whether it's a class or spec.
