having problems seeing full intellisense (code completion) options in PyCharm. working with python 3.4 on Windows. the suggests are partially working:
import bot
This is happening because all of the methods on the boto3 clients and resource objects are generated at runtime based on a JSON file that describes what operations the service supports. Pycharm would have to have specific knowledge about this process in order to auto complete method names.
For your second question, boto3 is the official AWS SDK for Python. One of the main advantages of boto3 is that because of this JSON model driven process that describes the AWS APIs, most new service features only require a simple model update. This means API updates happen in a quick, consistent, and reliable manner.
But if you're using boto in existing code and it's working for you, feel free to keep using it. You can always install boto3 along side boto if you need to pull in new functionality.