I found an open source 2D graphics library built on LWJGL called Slick that so far appears to do everything I need it to do, and has extensibility options for things I might need that it doesn't do.
I'm currently trying to figure out how I can distribute as much of the program's load as evenly as possible. I would like to set up a series of interdependent web services using various AWS services for the processing and exposing of data. This would make everything scalable on a finer level via loosely coupled components, rather than bogging down one machine which handles every task atomically. The issue there is, of course, timing/blocking and latency, but if I labor with that design pattern in mind, doing the actual uncoupling later will be much simpler.
Still working on the basic ecosystem model. Lots of boilerplate that, once set up, will allow much faster iteration through design ideas. Dynamically modifiable fuel system (nearly) in place with a persistent backing that can be exposed to the program from anywhere (local file or web service) and processed as a simple object with list of objects (ie, all fuel objects contain a list of children fuel objects). I've spent a bit of time on this part because it's the backbone of the entire model. I'd like to get it right the first time and not be forced into a rewrite in three months that sets me back a month.