Yeah, you can drive a vehicle with 250,000KMs (150,000miles) across the country without worrying. My buddy has a truck with 450,000KMs.
I can't stand ricers, espesically the entry level cars. Nissan does make good vehicles, but you can't waste your time buying the cheapest crap they make. You would be better off buying a more expensive used vehicle from 2005 and up. If you want to buy a $15,000 car brand new you're going to get what you paid for (trash).
Manual transmissions are great, they give you more control over the car. If you're an idiot it's alot easier to fck up alot of different things. You don't want to learn to drive a manual on a brand new car, but if you're going to buy entry level and base trim it really doesn't matter, it won't last long anyways. Mileage tends to be better as well, most vehicles offer a 4-speed automatic, or a 5-speed manual. The extra gear will keep your RPMs much lower on the highway, and in town you control where the shift points are.