Ummm coming from a lvl 41 bard.... Bards can main heal and off heal just fine.
We stack cast speed as opposed to g-heal. I'm sitting around 26% cast speed at the moment and it is definitely possible to hit 30% or 35% with real gear. That gives us plenty of throughput with Cure to main heal. Alot of people making statements about bards not being able to main heal are either undergeared or with tanks who are undergeared. A well geared tank should have a solid 35%+ mitigation and 50% combined evasion + block. When that happens I not only am able to main heal but I am usually able to keep up the HoT and a buff or two. Dispelling is also important, and it is a little harder as a bard so keep that in mind in fights where dispelling is a must. Sometimes you do get reduced to just cure, hot, dispel even with well geared players. To this point I have main healed every single instance up to Baltaroi core and have solo healed Ulta and Malice when the tanks were not in low level green gear.
We are certainly at our best when we are offhealing though. In a group where I am offhealing I am usually only needed to heal the DPS (with our group hot) and maybe occasionally throw a cure at the tank unless he is really undergeared. This usually lets me keep up War Rhyme, Illusions, Spirited Melody, and Burning Metal while tossing in nukes to try and knock the mob down, plus the acc debuff just means even less tank dmg. Unfortunately the Magic Dmg song is just not worth using most of the time, the dmg boost is too small to warrant it. I am sure our offhealing role will get supplemented even further at 50 with the G-Heal P-Heal buff song.
If you think we are DPS, thats funny. Our DPS is absolutely terrible in almost all regards. Burning Metal is "ok", its biggest advantage is not DPS but the huge triple stack defense reduction. Its even worth keeping it up on single target bosses just for that if you have the chance. Our dmg is terrible though, I can throw out 800-1500 point nukes while DPS classes are throwing out 2000-6000 point attacks. I'm sure that can get turned up a little bit if you stack the M-Crit leather but yeah..... If you really want to understand how bad our DPS is, play a real DPS class and compare. Yeah the buffs make up for some of it, but not enough to qualify us as worth having for a DPS slot when a group already has a healer + offhealer.
At least our AoE is tolerable, our single target is awful. A good mage or thief puts our aoe to shame though. I would imagine Blade Dancers will also make our AoE look pathetic.
Gear is a major factor. Get your hands on some agi/cast speed leather and you turn into a monster. Theres some agi/cast speed/gheal leather from bosses out there too that would probably make us incredible healers, maybe even better then clerics on raw throughput. Dunno how I can prove any of this though, I would simply assume that you aren't using bard stat leather if you are having trouble healing as a bard, or your tank has no clue what hes doing.
I look through what you said so far, and it looks like you know what your talking about, but then I really look at the numbers and see, wow, either your seriously exagerating, or playing with hackers.
I have stacked cast speed to as high as I can get it, and I only have 16% cast reduction, 25% if my Cast speed trinket activates. And a well geared tank at any level will have 25% defence, and 30% combined Block and Evasion, because stats scale with level, higher level means you need more to get the same effect as before. And if your reduced to Heal, HoT and Dispel, you just stoped being a bard and became a weaker cleric.
Off healing doesn't make you a healer, anyone with a heal spell can off heal, it's a general term for "Classes and players who aren't good enough to be the main healer". And why are you ignoring the Cleric buffs, they do give just a big a difference in how much they do for the team, and they last for 15 minutes each.
Your severely underestimating how good our DPS actually is, it seems incredibly low because your either spaming attack spells with a Cast speed/General Healing build, or smacking something with the guitar, which has pathetic damage with a Cast Speed/General Healing build. Triple Stack Burning Metal and Music of Life, throw up Spirited Melody and War Rhyme, Switch to a Great sword, you just started hitting as hard as any other Melee DPS, while at the same time made the rest of your physical attacking teammates hit harder, all of which counts as your own DPS because you caused all that bonus damage. Changing weapons is instant with no global cool down, and you don't need to use a guitar for anything besides casting, and with no duration buffs for any of those spells, you'll still get about 6 seconds to slash enemies with your sword before needing to switch back to the guitar and rebuff, why else would one of our buffs be "2% chance to double hit", if we weren't meant to use melee physically attack, bards were designed be versatile, with the right gear set up, they can go caster DPS, or Physical DPS, or Buffing, but they will never be able to compare to Clerics when it comes to healing.
Maybe a mage would, but theives only have 1 AoE attack, we have two, and thanks to the AoE cool down, Burning metal + Tornado will out damage a Thief AoEing, and a Blade Dancer uses our Physical DPS buffs and Burning Metal to make himself stronger.
Gear isn't everything, if you give a Cleric a similar Cloth armor Agi/Cast speed gear setup, they still heal faster then bards, and still for more, and Cloth armor usually comes with more cast speed anways, and with Grace of Wisdom on both the Cleric and tank means the cleric starts healing about twice as much as the bard will, and with a mace, easily faster, even Music of Life isn't neccisary if your cleric starts charging Healing Radiance as soon as the boss starts charging his AoE attack and everyone has Grace of wisdom, which they should, because it lasts for 15 minutes.