OK, first question has arisen already 
I notice when you send data to the screen it stays until something is written over it. When sending variable data text strings to the TFT, the results just keep overlaying each other. Sending tft.fillScreen(ST7735_BLACK); is very slow and it seems pointless re-writing any static text also.
Is there a simple way around it? I guess you could just write black squares over areas but that sounds like a nightmare to implement 
Also the wrong as some of you mentioned would be the case.