To answer your first question: yes it is feasible to develop an android application in pure python, in order to achieve this I suggest you use BeeWare, which is just a suite of python tools, that work together very well and they enable you to develop platform native applications in python.
checkout this video by the creator of BeeWare that perfectly explains and demonstrates it’s application
How it works
Android’s preferred language of implementation is Java – so if you want to write an Android application in Python, you need to have a way to run your Python code on a Java Virtual Machine. This is what VOC does. VOC is a transpiler – it takes Python source code, compiles it to CPython Bytecode, and then transpiles that bytecode into Java-compatible bytecode. The end result is that your Python source code files are compiled directly to a Java .class file, which can be packaged into an Android application.
VOC also allows you to access native Java objects as if they were Python objects, implement Java interfaces with Python classes, and subclass Java classes with Python classes. Using this, you can write an Android application directly against the native Android APIs.
Once you’ve written your native Android application, you can use Briefcase to package your Python code as an Android application.
Briefcase is a tool for converting a Python project into a standalone native application. You can package projects for:
You can check This native Android Tic Tac Toe app written in Python, using the BeeWare suite. on GitHub
in addition to the BeeWare tools, you’ll need to have a JDK and Android SDK installed to test run your application.
and to answer your second question: a good environment can be anything you are comfortable with be it a text editor and a command line, or an IDE, if you’re looking for a good python IDE I would suggest you try Pycharm, it has a community edition which is free, and it has a similar environment as android studio, due to to the fact that were made by the same company.
I hope this has been helpful