Also, everyone you give a green rating here will automatically become DT2 and his ratings will show in bold red or green as well.
This is incorrect. Leaving positive trust for another user if you are DT1 does not make them DT2. This is achieved by adding their name to your own individual trust list.
Please note that you have a responsibility regarding who you have in your trust list. You might give someone the power to rise to DT1 as well
This is true for every user with >10 earned merit, not just users who are currently DT1. Any user with >10 earned merit is voting for DT1 members via their own personal trust list.