1. The offer is clear, but as they say you need power before you can reason with others so, say you are SEO expert, your critical view of any related field would be most welcome, other might get ignored. So I'm thinking you would want to hire freelance experts for different fields, once you do that, or get them on-board you would be ready to give feedback of high quality. Best is to set a revenue share, 20-80%, in case sales happens, if not nothing. This will bring you lot of customers.

2. yes, its a steep price to ask, compare it to the fact that online lockers cost way less than that, yet hardly anyone gets premium occasionally!

0.99 and 1.99 per month sound more fair, given low quality feedback sites are absolutely free.