>>300223173
>or could I do something like cover the whole model in hair and make some kind of sasquatch?
You can make a sasquatch yes

>Could I draw directly on the face in an attempt to add wrinkles or definition?
Yes

>How much freedom is there in the creator? 
Quite a lot and the "sliders" can be overridden by by typing in a value for those weird shapes.

Overall It's a really amazing humanoid anime creator that is optimized to make good humanoid anime models.
The ease of use is it's best factor for sure compared to making things from scratch on blender.
Here's a video that might help you get started:
https://www.youtube.com/watch?v=3QZu9aAwAXM