Usually you need to set 21000 minimum gas for an ethereum transaction and this gas amount gets converted internally into ethereum.
By measuring current market, 21000 gas is equivalent to 0.001 Ether currently and may increase by time. Whether you initiate ether transaction or token transfer, the same gas amount is required every time for both transactions
Yes but in the past it was possible to make slow transactions with 2 gwei. Now it's not possible. The minimum is 40 or 50 gwei I think. This is the problem.