Commerce Stripe and 2.0 version of library with namespace?
Download the 2.x uc_stripe version of the gateway for Stripe - it has code that works (https://www.drupal.org/project/uc_stripe) as you are seeking - the version 2.0 library uses \Stripe\Action-to-Take:: instead of Stripe_Action-to-Take::  Stripe Connect however is a whole other issue requiring a OAuth2 flow and JSON working with the Stripe Webhooks to get it working initially and THEN one can use the API for the rest of the issues for nmaintainance