Actually, no. What you're describing would be a horrible system that could be abused by others (especially used against individuals). Bitcoin is pseudo-anonymous, which is definitely a "good mix" (being too anonymous would make regulation very hard, and being 'too little' would make it just too transparent). Some improvements are expected in the future when it comes to privacy (not the other way around).
I would always check if the site I will invest or the bitpal
How about just not investing in suspicious stuff and using common sense? I've never had a problem with scams in the last 3 years.
not all the way, because some of the transaction can be made within an encrypted location, that is what we can see. they can use the multisig wallet and/or Tor to evade this kind of exit scamming.
so do not trust the blockchain all the way.
What is a "encrypted location"? You might be talking about VPNs. Multisig wallets are a great way of preventing both scams and hacks if used properly. However, they still offer no guarantees that something bad won't happen.