I have started delving into python stuff for QGIS and my questions are not really of interest to most users of GIS SE.
Where should I ask questions about writing plugins and scripts for QGIS?
If your Python Questions are GIS specific then they are on-topic for GIS SE (Main). However, if they are pure Python, and would standalone with no mention of a GIS technology in them, then a more suitable place to ask them is Stack Overflow.
I wrote the above before spotting "qgis" on the end of your title. However, I think most if not all of it still applies so I will refrain from changing it for now. My understanding is that a question title should only summarise what is in the Question body, so if you are looking for Answers related specifically to QGIS then you may want to edit your Question to make that clear.