Yup. Tekkit is having some issue i haven't been able to resolve yet. Been busy this evening, so I haven't had sufficient time to focus on the issue. I am aware and actively working on it. Thanks!
*Sigh* it was ChickenChunks. AFTER telling users not to use ChickenChunk Loaders. I disabled the mod, and the server started. Whole time, not a single error or crash log. I am keeping ChickenChunks disabled for the time being. Use dimensional anchors. You will have issues with some dimensions not being force loaded on server start looks like. Sorry, we'll deal with it later. Most issues are waiting for the next update that I'm hoping will fix stuff. Just need to keep things running until then.