The only problem I've seem with Juggernauts is their lack of reach at low levels, making it easy for DPS to use their knockbacks to keep mobs away from you. This is also problematic for competent DPS, who keep seeing mobs knocked out of the area of effect of ground targeted abilities like Death From Above. It's not a problem with the tanking class, and could be easily solved by making Flashpoint mobs immune to knockback.
That would be awful. As a jugg tank leap --> force push --> leap is one of the only ways I have to quickly pull together spread out groups. (Edit, not to mention one of the most fun things I get to do as a tank.)