TravBot is a desktop application that runs on your computer. It works by creating a Google Chrome browser that it controls and can perform actions with like a human would.
Yes, it is important that you are aware of the risk and try to minimize the chances of getting banned by following best practices and not being obvious. The bot cannot do more than a human is capable of. If you make the bot perform repetitive actions for prolonged periods of time it is very likely that you will get banned.
No, but there might be in the future.
As of version 14.0 the bot supports managing multiple accounts at the same time.
According to the rules it is only allowed to play on your own account and those who set you as a sitter on a single travian server.
Otherwise in order to multi account, each account needs to have a unique IP address. There are many ways to achieve that. The easiest way would be to use a proxy server. That can be set for each account in its browser settings.
Also note that multiple accounts cannot share the same Chrome profile so you need to set a different chrome profile for each one.