Could you increase the limit on the bits for splitters to something much higher, like 128? If not, where in the code can I change this? Lastly, I tried importing the project into Eclipse, but had no luck. Is there a project for it somewhere, or do I have to import as file system?
The 32-bit limit on bit widths reaches pretty far across Logisim's code base. Changing it properly is likely to require quite a bit of work and to produce *lots* of bugs, so I'm not inclined to change it right now. I agree that it's a desirable goal, but it's more on my long-term radar for the moment.
I do all of Logisim's development within Eclipse, so I know it's possible. But I don't have instructions made up for how to set it up. Here's a quick rundown, though: The Subversion repository is not set up as an Eclipse project. Basically you want the trunk/dev directory as the base directory for your project. You'll want to include the JARs found in trunk/libs into your classpath. And trunk/scripts contains a Python script for creating a JAR library - though your mileage may easily vary on how useful it is.
I don't plan to provide further information on the subject. If anybody else wants to write up instructions for setting up Logisim in Eclipse, I'm sure they can do a better job than I can.