Hostile drivers are a definite obstacle, I agree. I'm not a big fan of bike lanes, though. Seattle has put in a lot of bike lanes recently, and I think they're counterproductive. They tend to be in the "door zone," which is obviously dangerous, and their installation has meant that streets that used to be two lanes in each direction are now one lane in each direction, with a bike lane at the edge. In my experience, this means that the car traffic now has no gaps; it's a long, slow procession of pissed-off motorists traveling in a single lane. This makes it hard to cross arterial streets, and to merge into traffic. Some streets that used to be pretty much ideal for cycling prior to bike lanes have now become dangerous for cyclists and pedestrians alike. I'm also worried that motorists will start to think that bicyclists should restrict themselves to streets that have bike lanes.
As for distances, I think anything within ten miles is very reasonable on a bike, it's not much slower than driving, especially if you factor in parking time. More than ten miles, for most people, it becomes an issue of how committed you are. For me personally, if it's ten miles or less, one way, I just ride automatically; it's probably easier than driving. If it's 10-15 miles, I think about how much time I have. If it's more than 15 miles, I'll usually take the bus or drive.