Without running through a mixer, aren't one's transactions are vulnerable to being followed through the network of addresses back to the point of origin, and forward to the destination?
Depends on where you first entered the 'system' that makes you reveal your identity. For example, if you buy on localbitcoins in a face to face exchange without the need of identification, it wouldn't be feasible to track the Bitcoins to your real identity. Sovereign money to Bitcoin conversion is the spot where identities are revealed. Otherwise, it remains pseudonymous.