You have a good mishmash... Lets break each one down... A lot of your stuff is wifi and cannot be run locally and will require an integration (if one even exists) for that product.
Can be used for TTS. Install the built in chromecast integration
You need to install the nest API. Read this thread [RELEASE] Google SDM API - Nest integration
This should pair directly to hubitat. (It will need to be factory reset first).
I would use a smart switch with smart bulb capability to control the lights. Use the built in bond integration to control the fan and anything else connected to the bond bridge.
Is this wifi or zigbee? If wifi there is a community built tuya cloud integration available in hubitat package manager.
Likely need someone to build an integration if an API is available. Ir if you could rig a dry contact
No clue
No clue
