Hi,
Yeah, I have some experience with Parse and unfortunalty, they enforce a unique username within the database, so this leads to a lot of not happy end users, because both have to be unique and that's completly unecessary. the email is the unique identifier.
So, I strongly recommand registering user via email only, this is way more efficient, cause that's the only information you need to track a user, the username is junk in terms of meaning and only clutter the user interface and leads to people forgot their combination of usernames and emails... I have logs of users failing dozens of times because they have so many emails and so many variants of their username that they lost it completly...
I'll add the username field, but be careful, this is a death trap.
The parse Proxy is only a set of helpers for me to provide easy actions setup. None of it belongs to the Parse API per say. That's why you are getting confused.
The proxy is here to solve a major issue with parse... monthly payments
you don't want that I know, and so I cache the object ID so that you don't have to get it over and over again during a session which is metered by parse to charge you, so the less requests you make to parse the cheaper for you.
that's all the proxy is doing. It's not related at all to parse api itself, I am only caching things up ( which is a shame cause they have a caching system on IOS and android, but they did not provided one for unity... cause obviously, they loose money)
the parse documentation is all on their website,
https://parse.com/docs/unity_guide#unity_guideBye,
Jean