I'm a visual person too, that's why some benevolent creature(s) devised google maps for us. If you don't know already, you can drag the little orange man to the street and get a street view in any of these places.
http://tinyurl.com/sheetz-to-1st-ave
Google estimates that as a 36 minute walk, one way, if you know where you're going. He would have had to hustle, which doesn't seem to be his thing, and there's no reason why he would have rushed back for a leisurely meal at the Huddle house, which is just north of the Sheetz. He could very easily had a meal and then walked to the house, done anything he wanted to do, and then called a taxi. He didn't though. The loss of the car may explain that, but it seems to me he was done there. One random thought that pops into my head regarding that is that I'm surprised he didn't burn the place down.
By the way, on that map, the house where the murder's occurred, 505 1st Ave., isn't correctly identified. It's the one on the West side of 1St. Ave. at the South end of the ball field. Its isolation probably had something to do with no neighbors hearing or smelling anything.
http://tinyurl.com/poorhouse-site
I'm guessing the tow truck driver knew the area pretty well and/or had GPS. His route back to town would very likely have been West on 637, North on 630, and North West on 628, which would have brought them back to Rt. 15 very close to Sheetz.
I think McCroskey was lost on Poorhouse Road. Like I wrote before, it can be very difficult to turn around on a rural road without getting stuck. I've had to unstick myself more than once while trying to do that. Why that road it's hard to say, but the same could be said for choosing it as a dumping ground. 460 is the start of the way to the airport though.
There may have been more to his being on that road, but he's hardly fit, and I can't imagine him picking up one body let alone 4, especially when one seems to have been a fairly large man. I don't remember the car model, but I'm pretty sure it's a compact to mid-size import. That means one body per trip if they're in the trunk. I don't get the impression that he is brilliant at all, but he would have had to have given that at least a bit of thought.
On the topic of McCroskey's fitness, I'm surprised at the identification of a maul as the murder weapon. I've split my fair share of wood, and those are hard to swing, at least with any sort of accuracy. The heads are usually around 5-8 lbs. Once it's swung, you have to pick it back up which takes some effort, and I would expect it to be stuck as well, if you can pardon the image that conjures. It would be hard for a strong person to do that quickly and repeatedly. I wonder how a kid from another world, who (I'm guessing here) hasn't likely split a whole lot of firewood, could handle it so quickly and effectively. I can't imagine al three females sleeping in the same room, so he would have had to do it very quickly on the run or very quietly. An unweighted stick would be much quicker, which probably explains why that's what killed the pastor. I wonder if the maul might have been used to finish up a job he started with something else.