I scrolled through your whitepaper and i like the idea a lot! But i still have a few questions which didn't get awnsered by looking at your whitepaper.
Thanks! Let's dive in...
1) The credit ceiling of a seller can be decreased. But how does it exactly get decreased? With a reputation of <3 stars? Or does it need several bad reputations?
The exact mechanism is not made public to prevent manipulation. I can tell you that it would depend on several factors, the primary one being the magnitude of the difference between the expectation that was set with the buyer and the actual result. It also, as you noted, is dependent on our confidence in this assessment (based on historical data).
2) How do you secure yourself (or the buyer) from an exit scam of a seller with a high credit ceiling? Are personal information gathered somehow?
We perform Know Your Customer (KYC) checks on all sellers. This is required by law in many jurisdictions, and also helps prevent some obvious attack vectors (like a Sybil attack). We describe this in detail in the Section 4.3.2 Advance Payment:
3) In theory a seller could "sell" products to his own accouts to gain a good reputation / high credit ceiling. Did i miss something in the whitepaper here?
Another great question Bob! You're thinking of many different attack vectors that this solution might be susceptible to, and we've got this one covered too. Section 4.3.2 comes to the rescue once more:
The first facet of this solution is to prevent sellers from accumulating a high reputation in a short period of time through “fake” transactions. Here, we note various signature traits of a transaction (device fingerprint, IP address, source of funds and other patterns) to detect and reject repeated fraudulent transactions originating from a single buyer (or a network of illegitimate buyers). The mechanism used here is similar to the one described in the prior section on Buyer Protection abuse prevention. Further, the reputation calculation mechanism limits what proportion of one’s reputation can originate from a single party.
Thanks for taking the time to ask these great questions!
I would like to post a few questions and hope to here the replies from your team. 
