This scheme also feels inherently exploitable as it relies on all parties behaving honestly to function... which is somewhat ironic given all the astroturfing happening in this very post.

AD: I hear you, we've just launched and money is our first and most generalised form of staking, expect more to come.

Endorsements remind me on how bank loans work. For every loan transaction that exists a collateral security or deposit is required to acquire the loan. Same can be said to this idea of endorsements -an amount of money (collateral security / deposit) to endorse the candidate and backs their skills / talent to get the role.