My opinion is a bit negative for the integration of Python in Blender. Personally I prefer using just Python without Blender. Grow your skills in pure Python development, so after a while you get the glue to use for example OpenGL or other geometric or image packages. GUI design is a problem by itself, for me there is no favourite GUI toolkit, and I have found it very frustrating. I’m about hoping Blender will have an own Python powered GUI toolkit some time in future, and maybe planning it while you learn Python, would be a nice and instructive ideal.
I’m thinking that the pythonic way would be something like this:
>>> from blender3 import *
[something instructive here,...]
This is not possible yet, but working towards the goal would surely be at least educational.