My first character was a BS/Inv Scrapper/terrier. I've ran him up to lvl 50 now. Got a bit shakey around the mid thirties, but Unstoppable more than made up for it. If you don't take Resist Elements or Resist Energy then expect non-smashing/lethal damage to sting.
On the other hand nothing dishing out smashing/lethal isn't going to bother you.
You are a rock with a sword.