The word "thankfulness" is an abstract noun. It can be stated as an adjective or verb. Alternate translation: "so we are very thankful and we welcome everything that you do" or "so we thank you very much and welcome everything that you do" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
"Governor Felix, who deserves greatest honor." Felix was the roman governor over the whole region. See how you translated a similar phrase in [Acts 23:25](../23/25.md).