For instance, they could clarify whether they will use a 2-of-3 multisig setup or a regular address for receiving payments. Using a regular address for receiving payments, for example, could potentially put users at risk, as a scammer could simply run off with the money.
Even if op uses a 2-of-3 multisig wallet that they control all keys, then it changes nothing, except op is going to control one key and his customers will control another key. However, i don't think a multisig wallet is in op's plans, if it was then they would have told us, op just wants us to believe that they are reputable enough to handle this.