CUT was an interesting "terminal". It was a combination of a through station and a terminus, as most of the railroads that used CUT didn't run trains through the station. The only exception was the B&O, which ran the National Limited and a few other trains that used it as a through station. The good thing about it's design is that the trains don't have to be pulled out of the station, so after they are done unloading, the trains can be pulled straight out and into the yard. I've made attempts at making it in the past, but I've gotten halted by the fact that there are no DEMs of the area.
As for your idea, CUT already had a sizable engine terminal and multiple coach yards. I'm not sure if railroads ran commuter service out of CUT, but in it's heyday in the late 30's up until the early 50's, it was a pretty busy terminal. The C&O, L&N, PRR, and NYC were all major passenger carriers, and you could be sure that trains from every one of those railroads would be departing on the hour. Couple that with preparations for each of the trains (pushing them into the terminal, pulling them out, adding cars, etc), and you have a pretty busy terminal!