Weekdays are hard for me to document the approach because i only get half an hour in my lunch time to work on this project and then when you are stuck you just want the answer before you can write something.
I finally decided to put my tools down and summarise the approaches and findings. Well, first things first. I was right in my previous post that i was not using the compatible Firmata version for ESP8266 which lead me to investigate if it is actually compatible with ESP8266. The latest versions are compatible with Firmata according to the documentation. Many people have used this approach to talk to their devices using different languages.
Anyways, back to the main thing again. No, i have not yet been able to get Firmata work with ESP8266. I am still investigating the problem. So my next approach after all those findings is to ditch the real hardware world and use Fritzing and test my code there. If it is what it seems like meaning that i can test my code on the virtual hardware then implementation would become very easy.
Hopes are high, fingers crossed!