Do we need regulations in the crypto world?
In the current situation that cryptocurrency is facing, I would say yes we need regulations. Governments are doing their own initiative to declare regulations so we are heading there and we have no choice but to follow it.
Should only ICO be regulated or legit coins (not "security tokens") too?
All crypto's.
Can we implement regulations mechanisms in code so that corrupted governmental institutions couldn't manipulate the industry?
Only officials has the authority to this.
Can we still have free market with governments' regulations across the world?
Yes.
Does could affect the number of investors involve in the crypto currency? Regulating our trades in not a problem. Its how the government could control our earning specially when it comes with the tax involve. I think the good benefit of it is the whole world can recognize the whale which we could prevent from pump and dump. I mage the scale of lost if they can still control this kind of big whale that could also destroy good platforms.