1. Fiverr need to make "partial refunds" easier.
2. Fiverr should start custom contracts for some kind of orders where sellers can take advance on their own terms, preferably, non refundable advance because some projects take a lot of time and fiverr supports only buyer.
3. When someone asks for a revision, revision time should be added to final delivery time of order. Some project revisions takes so much time and it results in disturbing "on time delivery" rankings.