Now Google home via cloud. What to do with the 'old' one?

Few months ago a switched to using Google Home/Assistant via the cloud setup. However I still also have my ‘old’ stuff setup before the ‘cloud’ version came up.

Can I just delete everything related to the old setup from HASS incl. the actions etc. I created in the Google cloud dev console etc.?

Yes you can. I’ve not cleaned up my cloud project yet, but I’ve disabled it in HA.

Out of interest, have you guys seen any benefits to switching to ha cloud?

A “sens of trust” for putting all your private stuff somewhere in the cloud?.. sorry for the sarcasm but this defeats the only thing that made me choose HA in the first place. Would you give your house key to some random stranger? I would not but this is my personal choice.

You don’t have to use HA cloud but if you want to use any voice control device you will have to open your HA to the world in one way or another. At least until a locally hosted installation becomes viable.

If you go the normal Alexa/google route then you need to open up your own router ports. With HA cloud it’s taken care of in HA. Either way ports are open. As of now I like the HA management of the port. I don’t know if either way is any more or less secure but I like that I haven’t “intentionally” opened an obvious, commonly scanned port on my router.