Sharetribe Customisation (RoR)

I have a fresh self-hosted Sharetribe (Ubuntu 16.04 on DigitalOcean) in need of customisation as an events website: I would like somebody who has good knowledge of Sharetribe as well as other platforms, with good communication to deliver high quality work. Requirements: 1) Customise Sharetribe with the standard landing page [login to view URL] - I can customise this later with the specific categories etc. 2) Add in the option for custom field listing for vendors to include attachments (pdf/doc etc) that would serve as a 'specification' or 'timetable' for the event. 3) Add in a generated QR code similar to what happens in Eventbrite/Attendize. 4) Add in the option of a customer to still 'purchase' a ticket even when it is free - currently on Sharetribe, this isn't possible as a free event just gets dealt with in a messaging system. 5) Include a dynamic review/feedback mechanism that can be sent by the Vendor after the event. This would be a form that the vendor could customise. The feedback mechanism can either be incorporated within Sharetribe if possible or on a subdomain e.g - feedback.domain.co.uk. Once feedback is submitted, an 'attendance certificate' is sent out to the customer. I can give you further details and specs once you show interest. Please suggest other ways of doing this if you have an alternative.