A new class that is purely support class?

I've enjoyed white mage and bard classes the most in the game so far. I especially like the party support functions of a bard. I think a class, possibly blue/red mage title, that would be purely party support. The class would not dps, tank, or heal. It would cast buffing dots on party members, either increasing dps attack stats, buffing healers stats, or defensive buffs for tanks. There could even be debuff spells that actually work on bosses such as a % defense or attack weaken. Another great skill to have would be float. Float could be affective for 1-3 seconds to help a player avoid a aoe plume. Putting float on the whole party would be a little much, but being able to cast it on 1 party member would be a great skill that would affect the overall mechanics of the fight.
The new support class limit break could be a party wide massive buff in all stats.

Its ok a Great idea. But a party is formed of 4 persons. 2 dps a tank a hlr. Now this support should be placed on dps i guesa since it cant heal....and the party would hav just 1 dps...

Would it be balanced?

I would see a support only role viable to a 8 man raid or 24 man. Even then that support better be damn good considering you'll be giving up at least 400-450 dps for it.

I was thinking something similar about it being primarily useful in a 8 player party. For a 4 player dungeon much of the bard support skills are useless, foe probably being the only useful one. I think it could balance out well if the class could increase the damage of each dps by 150. So 3 x 150 = 450. Or if focusing on healer and tank buffs, would essentially make having 2 healers in and 8 player raid/trial unnecessary. I guess the point of the class would be the ability to boost healer or tank attributes when needed or boost dps when needed. Every fight in the game is different and different party make ups to optimize each fight. Sometimes solo healing or solo tanking are best, but there's 1 part in the fight where having 2 would be nice. If there was a class that could boost whatever was needed during each phase of a fight, that would be a very convenient class.