about the clark disguise:
it really is about projection, as mentioned here several times, superman projects confidence, power, authority, altogether a different persona, while clark projects a different personality. Granted they look a like, but it can and does work.
fact #1: elvis joined an elvis look-a-like contest in a US burger bar during the 70s and guess what, he only won 3rd place.
fact #2: arnold schwarzenegger joined a radio contest on who sounds most like arnold himself, and guess what, he lost.
you see, without us knowing that it's the same person, the same actor, sometimes it can be overlooked. A certain level of suspension of disbelief is still required, but I think the explanation of different personalities and demeanor between clark and superman already works and is fine for me.