Are you talking the platform itself? It is very secure but once you downloaded it make sure you have a virus protection on your computer so that no one can access on your account.

What are you talking? secure against losses or against cyber crime. Install Anti-virus on your pc to have a safe trading. Manage your account properly to generate more profits!

It depends to the broker you are using. If you are using an unregulated broker, then it's definitely not a safe broker to trade with.

I think you are referring to the web-trader platform where everyone can trade automatically using the platform of the broker. Maybe yes or may be no because there's a possibility that they might manipulate the connection from its servers if you are making money.