You really shouldn't be dying much if you're using Blood Rush constantly - possibly never taking ANY damage. With that said, toughness doesn't matter too much if you're dodging range attacks and Blood Rushing to elites. Maybe you need more CDR so you can Blood Rush more.
That's why I stopped playing Trang's. The reason it dominates the leaderboard is because it's a kite and nuke with cooldowns strategy. You should watch some videos of high tier GRs and use those strategies.
I find that play style really boring, so I went with a more fighty Inarius build