You could lock down your interaction with the SR web site in such a way that you would be safe, even if it the server was controlled by LE and serving exploits like the FH server was. First, to prevent being identified, you should encrypt your shipping address and make the vendor encrypt any tracking numbers that he sends you. This resists the simple reading of information that can be used to identify you. Second, disable scripts and plugins in Tor Browser, and use physical or virtual isolation between Tor Browser and the Tor client. This will resist active attempts to identify you, such as exploits designed to grab your IP and MAC addresses. Third, separate your identify from SR in the bitcoin trail, either by purchasing coins anonymously or mixing them properly in a trusted mixer, or as a vendor, taking similar steps to cash out in a way that separates your vendor account from your identity.