Hey! thanks for be interesting in my project.
Really, I offer a lot of apologies for leaving it a little abandoned, I've been busy with other Alexa and Cayenne projects. But these days I'm going to take over this project again.
First, this project get a connection between Alexa & Cayenne (via MQTT Server), if you want see reflected actions in Raspberry, you must to install a MQTT Client in Raspy (like Mosquitto) and suscribe to Cayenne MQTT Channel, you can use a Raspy or any compatible board.
For phrase, unfortunately when you create your own skills, this skill name must be in the invocation phrase; but Alexa is able for detect "Alexa, lights off" phrase, but that is only with compatible devices (like smart bulbs of philips, or some official products), for the rest you have to tell the Skill Name, you can use a friendly phrase for that, for example, for automatize my house I'm thinking in create a Skill called "Daxes Home", then I can tell to Alexa... "Alexa, launch Daxes Home and turn off my Beedroom", or "Alexa, ask Daxes Home for Blind Up kitchen"
For now, I can improve my project for able to understand more friendly commands, like "Beedroom, Kitchen, Room", You have to attach after, each Topic (from MQTT Channel) to any pin that you want.
Let me first to work in the Skill and after try attach that in Raspy, but I will spend some time in that, if you need fast help, you can contact me I promise help you.