You're from Toronto and worrying about bad drivers elsewhere? I've driven through most of the US and there's a heck of a lot more common sense behind the wheel over there than there is in the golden horseshoe. You'll also get fewer left lane bandits, with one exception - they allow big rigs in the passing lane and sometimes they'll take miles upon miles for one snail (that prick who swerved in front of you and REALLY made you lay on your brakes) to pass the other. Especially beware the rigs with the stickers saying "Without trucks, America stops" as the guys who stick those believe they should be treated like royalty. Still, people won't routinely camp in the passing lane, they're more likely to signal and less likely to have random moments.
Watch out for the popo as speeding tickets are an officially recognized tax collection method, where municipalities even have set percentages of the budget they are allowed to finance by fleecing (mostly) tourists. Your "Yours to discover" plates will be a big bullseye for every uniformed tax collector on the way. Make sure all the equipment on your truck works (horn, wipers, lights, etc etc etc) as they will go over it with a fine-toothed comb for value-added tickets. Try to set your cruise control to just below the speed limit, but not too much below as you'll get nailed for obstruction. That will mostly keep you safe, but not absolutely as "eyeballing it" is an officially recognized way to "measure" your speed in their courts and has even been used to defeat GPS logs. It has a fancy name "visual speed estimation" or something along those lines.