Interesting project.  There are a few points which come to mind.  Seen this type of business on the web & think that there is one major point in that the 'expert' appointed must be a true 'expert' in the field .  For example, a Lawyer asked a technical issue of law in the Country you reside in must be able to fully understand your question & the 'background ' of the question.   It is very difficult to satisfy someone via a short 'conversation' or text if the subset of the question is not in the area of expertize.

A second point is how can you be satisfied with your 'experts' unless there is a considerable amount of vetting & monitoring.  All this takes time & who pays for that time.  A busy 'expert' in their own profession would not be interested, yet the is the type of person you want.  Someone with time on their hands may not be a worthwhile expert.