To be honest, 80% of level 3 is useless, at least for my daily job.
As to ethics, guys, don't think US is paradise. Stricter regulation is true, but definitely still lots of insider information and rumors on the street everyday.
The criteria is: Don't abuse it.
Well, I work for a fundamental oriented fund not a quant shop, so those trading strategies such as VWAP, implementation shortfall are totally bullshit to us. Maybe useful for algorithm trading shops, i have no idea then.
Level 1 and part of level 2 are definitely helpful, but just very basic knowledge. You can not rely on CFA stuff to be a great investor.
The short answer is yes, if you're working in Asset management or PE/IB in US. But for the personal investment, because the knowledge system of CFA does NOT cover Technical Analysis or Trading Strategy, so it's quite limited.