You are right to think about how the short wheelbase of you truck will handle a long trailer like that. I don't believe listed the weight of that trailer is accurate. I would see if the options, like a/c, generator....are included, just seems way to light for a 34' toyhauler.
I had a 26' and it was in the 11,000 lbs range loaded (didn't know that when I bought it, just went of the mfg specs), oh yeah and its advertised weight was 5500 lbs, oh yeah I tried towing it with a 1/2 ton truck with a 9000 lbs towing capacity. I then moved to a bigger truck