Check the npc in forest as you got told. Also I think I heard someone saying that to raise properly instrument skill, you should sing one song at a time (to raise it, not in fight) so maybe if you can leave your bard singing while afk, it will raise up. Not sure about that though.
About bard being useless in fight because mobs are down too fast there are few things :
1) Make sure when you pull (if it's a pull) to bring mobs close to him, so you just have to switch windown and push /assist warriorname. You won't have to move your bard then, just to push the button. I don't remember if you are using MQ, that's why I am talking about the good old assist button (with /assist on, so bard will auto attack when asssisting).
2) Bots have the great ability to react very fast, unlike players. On low hp mob, it's true that your bard won't always have time to attack, that's true and not only for your bard (will be the same for any other dps class, unless wiz with instant cast maybe). But keep in mind that you will progress through tiers and that mobs will have more and more hp. You will have plenty of time to attack with your bard in Ssra, kael, tov and following tiers.
3) Shaman are great, no doubt on that. Gladiator and Spirit of Lion line are great for dps and they heal pretty well (I wouldn't leave aside my shaman). But you can forget their slow because, as it's been said, slow is resisted (or just immune mobs) so often in late tiers (even ldon ones) that I don't bother meming it anymore. Keep going the bard, honestly.
And forget about the shaman pet. His dps is as ridiculous as his ability to survive. Mine was already dying all the time in early tiers. So no regret on that side

4) You will enjoy the Faded Memories AA of bard and the dps / support it can bring. Anyway, if you change your mind later, it will be fast to level up the shaman with your warrior, but keep working on bard.
5) Your bot rogue is doing pretty well now, but as you progress, his dps won't be enough and you will need more and you will need a dps that can stay alive longer than the bot (thanks to AAs that bots don't have). Your bard will then be good in my opinion.
Just two questions : where do you stand in progression atm ? Where are you fighting ?