1: if you can compile the firmware yourself, there is a simple way to switch to HTTPS: in main.cpp, change the include file BlynkSimpleEsp8266.h to BlynkSimpleEsp8266_SSL.h that’s it. We did test this internally and found that the response speed can be slow: something when you click on the button in Blynk app it doesn’t response immediately, which we think is not great for user experience, and for that reason still using HTTP.
2. The OpenGarage API already provides open and close features thought HTTP API:
section 3 on the first page.