I'm not a big fan of using proof of burn for reputation as planned. I want to propose an alternative. I think although these ideas are more complex they are more useful.
Every username would have a birthday and three reputation metrics or scores:
Everything builds off the devotion metric which is accomplished by mining your user name via coin-day mining "CDM". Essentially you can point a balance to a user name to increase (or decrease) it's devotion score proportional to the coin days of the stake directed toward the user name. This metric is scarce because a given balance cannot mine multiple usernames at the same time. Multiple balances can however mine a single username concurrently.
The process starts when someone pays a reasonable fee to register a username. This initiates a 30 day "auction" that is decided by competitive coin-day mining. If no one else competes for the username or mines against it, than the person who registered it/mined it the most gets it after 30days. This date is the "birthday" of the user name.
The devotion score for a user name is generally given by the formula: supportive_CDM - opposing_CDM = devotion.
Any username may choose to trust, not trust, or remain neutral toward another username. The user name's total trust score is determined by the sum of the devotion scores of all usernames who trust it minus the sum of the devotion scores of all usernames who distrust it.
The lifespan for most accounts will be equivalent to the age of the account since the birthdate and goes up with time. However if a username's total devotion score is brought negative by opposing CDM, the lifespan instead decreases with time for as long as the devotion score remains negative. If a username's lifespan goes to zero, the user "dies" (username is revoked and it may be re-registered by someone else.)
The robo-hash images can hash both the username and the birthdate so that if a username ever changes hands the robo-hash image also changes.
Most names will have positive metrics for all three and the more positive the better.
If there is a user you don't trust you can simply distrust the user and encourage others to do the same. Any name with a negative trust score should typically not be trusted.
If the user is particularly offensive or the username is an attempt to spoof, you can opposition mine the name to destroy it's devotion score and eventually kill it/get it revoked. Any name with a negative devotion score is a huge red flag. This account is quite likely a spoof/fake name and is on the road to revocation unless they can mine it to bring it positive. There would be BIG warnings before sending any funds to a username with negative devotion.
The longer you have maintained your username in good standing the longer your lifespan and the longer time you have to react if someone starts opposition mining your username.
During the initial auction if there is more opposing CDM than the highest user competing to own the name then the name is never created. So if someone tries to register an offensive name we can neg-mine it and it is killed in utero.
If you want to take a real close look at a username you can see specifically who trusts them, who doesn't, how recently was their devotion mined etc.
There is a natural opposition between trust & reputation and anonymity/privacy. My feeling is that anonymity has generally been overemphasized at the expense of more important things.