If they can be controlled from hubitat, you can expose them as switches and contact sensors to Echo through the Echoskill. In some cases you can use a virtual switch to control something on hubitat then expose that virtual switch to echo as well. Fibaro can be controlled with hubitat, but switchbot needs their hub integrated in to HE then you expose it. If you haven't already, look here on how to bring switchbot into HE. In some cases to kick a routine on echo I use a switch to contact sensor driver to kick an alexa routine for a device I can't connect directly to hubitat.
For fan controller, see my reply above. For the 12v thermostat, I am unsure about that.
