mr dave

Short answer - no.

Long answer - How is that different than asking for lessons / tips RIGHT HERE? How would it compete with youtube? If you load up youtube right now and search for 'guitar lessons' you get 218 000 results. 35 000 specifically for beginners. Piano lessons - 45 000. Drum lessons - 40 000. Like it or not any potential site idea you have of this nature IS going to be directly compared to youtube.

How do you plan on paying for those professional teachers? How do you plan on not having their lessons stolen and circulated for free after their first publication? The only real way around that is to make it a private (read: PAID) service. Why would anyone pay for online lessons when the vast majority of those same people could pay similar amounts to have personal face to face lessons?

That badges / levels thing you describe is inane as well, sure it's a way of tracking progress within the training mode in Rockband on ps3 or xbox but actually learning to play music isn't a competition, there's no checklist that upon being filled to X amount means you're a for really real musician now. No one who isn't involved with that service would honestly give a crap about what badges / trophies you have on some online profile as opposed to just wanting to hear what you can do with the instrument.

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