Glad to hear your getting it sorted out. I have my new to me 07 Inferno limited coupe now sorted out too. I was correct. I did not have the transponder kit in my Key and my skreem had gone into a lockdown mode shutting it all down. I had left the battery disconnected overnight, put the transponder in the key then reconnected the battery and it started right up.
So grateful for the forum and all the good people in the Crossfire community like Miami Matt who has also helped me tremendously.