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.
Recently SwitchBot has released their SwitchBotAPI.
I've created a small driver to control my Bot devices directly from my HE7 hub without IFTTT.
In case any of you are looking how to connect your SwitchBot bot to HE7, you can the driver here:
hubitat/Drivers/api-bot · toffehoff/hubitat (github.com)
Personally, I would have loved to be able to interact with my SB hub directly, so I would my home-setup run locally. But alas.
On a positive note, using the SwitchBotAPI (instead of IFT…