It is a disadvantage of P2P transfers that most bookies, especially in Europe, don't accept them. Nevertheless, most offshore bookies allow deposits and withdrawals through them.
Most P2P transfer methods accept multiple currencies. Depending on the company that you will opt for, before you proceed with any deposit, you can ask if you can use your local currency to avoid any conversion fees.
All these companies that you can use for person to person transfers have legal licenses from multiple authorities in order to allow you to transfer money internationally or locally. Thus, your transactions are always safe and secure.
Most of these payments allow withdrawals to players. However, sometimes it depends on your bookmaker. Several of them don’t allow withdrawals with P2P transfers and players need to find an alternative method to withdraw their winnings.