* funding terrorist,
* money laundering,
*kidnap for ransom using bitcoin, and etc,
These are not arguments against Bitcoin, they're arguments against currency. Every currency in the world (primarily the US Dollar) has been used for illegal activity. Eliminating a currency will not eliminate the funding of illegal activity.
Saying that Bitcoin causes terrorism, therefore we shouldn't use bitcoin is like saying cars kill people, therefore we shouldn't drive cars.
* when you buy bitcoin cheap you earn, while others buy bitcoin which is expensive they lose.
* The rich people could earn more in investing bitcoin while poor people could lose more. (vice versa the rich people may lose more and poor people can earn more)
* the use of bitcoin to travel spending outside in the country is more like selling your country asset and that could destroy the economy of that certain country.
Bitcoin gains or losses does not favor the rich more than the poor. Everyone buys bitcoin and different times, with different cost basises.