If you want to be a productive realtor I would go with a larger brokerage that has the tools and training to help.

When they responded to the email they did not answer any of my questions, so I politely asked again.

They give you some great tools, and they also have some great training/info on this very subject. 

Can anyone tell me if there is a tool on the website to find accurate rent numbers 

The agent that told you that is correct, however commission is negotiable, you can offer them a lower rate to list a property or use it as a negotiating tool in their next purchase assuming your broker approves, also it incentivizes them to use you again for their next purchase.

But I haven’t found a tool for NY yet, specifically NYC, any tips?

It can be a useful tool and has many positives, but man do those edge-cases really burn!

I've heard of using List Source as a tool to collect addresses of properties. 

I can set much more refined search criteria and I have access to other tools that allow me to mine for properties based on distress, absentee owners, etc.

There are definitely some tools that can help with streamlining this process.