As a pro user of imaging apps for last 20 years I have personal opinion. Maybe you should leave RAW support (Develop Persona) and Liquify Persona as is for now and concentrate on basic functionality like contextual menus and info palettes, brushes, painting, cloning, working with layers, smart objects etc.
Most pros (people who works with RAW images) have already some kind of RAW development app for that. (CaptureOne, Aperture, Lightroom or many others)
I am not sure how many developers you have but this app is very promising and I will buy it asap. You can always come back to RAW or liquify features in version 2 or 3 of the program.