I think the HoT should be a group HoT so it affects all in the group including the Lion. The juggernaut is more of a support tank than anything. The dmg output is quite low compared to other classes. I realize this is good as the juggernaut is a great tank, but making the HoT affect all would be a welcomed addition to his group of skills.
The self buff duration is very short. If it could be either longer duration or castable in combat it would improve the class a bit. As it stands as soon as you lose the buffs you turn into a squishy mess with sub par dmg. The Juggernaut is a great tank, but has very low dmg. Improving the duration of the buffs or making them castable in combat would increase the tanking abilities.
It would be great if when specced jugger shield it would increase your weaponskill accordingly. As of now jugger shield spec doesn't increase your weaponskill at all according to shield worn. This would help to increase base dmg a bit with shield spec.