Yes, the aisle industry is a good idea. I read that same MR article, and there has been another one recently about "front flats" which is about the same concept. I actually have two of those planned on my layout.
Your idea about the oil industry is solid, too. You could also add boxcars of drilling mud to that list.
Regarding other industries,
http://www.historicaerials.com shows what appears to be a cotton warehouse on the south side of the tracks about two or three blocks off the mainline near main street. There's also another industry of some kind about a block closer and a block to the east but it's unclear what it is. There does appear to be a smallish elevator on the east side of town. Outside of that, what appears to be maybe some team tracks near the station but they could just be station tracks, too. I'm not by any means suggesting you have to model it verbatim....quite the contrary since I already floated the idea of moving the gypsum plant. Just trying to help with research about what is there. The cotton gin/warehouse wouldn't be a compact structure either.
