"The orthodox call that part salvation and I would presume that to not attain this Christ-likeness or theosis means one didn't end up attaining salvation? Or am I wrong there about what Orthodoxy teaches?"
Yes and no. It really isn't that simple. So very few people attain a complete similitude to Christ in this life that one can only hope that something less, in God's mercy, will cut it. I think its a safe bet that Orthodoxy would hold that unless one attains some similitude to Christ, then one is the vine which bears bad fruit and is destined to be cut down and burned. We believe that we all have access to the same grace. Some respond, become like Christ and love God and so God's love is paradise to them. Others don't respond and grow to hate God. His love is an eternal torment to them. Same love, different effect.
What did Christ's death do in the view of Orthodoxy?