If I drive this display at very high speeds I get 'video tearing' effects, how can I synchronize the display refreshes?
We don't break out the TE (tearing effect line) because we use these with small microcontrollers, but if you do need to synchronize you can solder to the TE pad on the TFT using fine silicone wire. (See this forum thread)
Display does not work on initial power but does work after a reset.
The display driver circuit needs a small amount of time to be ready after initial power. If your code tries to write to the display too soon, it may not be ready. It will work on reset since that typically does not cycle power. If you are having this issue, try adding a small amount of delay before trying to write to the display.
In Arduino, use delay() to add a few milliseconds before calling tft.begin(). Adjust the amount of delay as needed to see how little you can get away with for your specific setup.