I went with option (c) above. The source/result/environment search now works fully, and one can make GET requests, like so:
http://173.31.182.88:8080/guscd/action.php?source=e&result=i&env=n
I will be away on vacation for the next week, and unable to access the computer that the server is running on, and I don't have time to write all of the editor functions before then. So if anyone wants to help transcribe the Index Diachronica, or add their own [potentially more reliable] sound changes—which I would appreciate very much—
here is a Google spreadsheet with which to do so.