I know it says it’s E2EE and open source but I wanted to check on the communities thoughts before I paid for it.
Why do you need HA to be in the cloud? Is self-hosting (perhaps on a HA Green if you don’t already own suitable hardware) not an option?
I run a HA VA fully local. It is effectively lobotomized; will often tell me there are no lights in my kitchen when I asked for the time. I often find myself debating the costs v merits of HA remote processing
No one can guarantee what happens on their servers.
But the stance of the company (OpenHome Foundation) is quite strong when it comes down to privacy. 
How do I access my HA when I’m not home, though?
You don’t, or use a VPN.
I have a VPN set up and hardly ever use it to access HA, so it isn’t really needed IMO if you have your automations and other things in HA properly set up.
Valid
To be fair, I can imagine some use cases for the VPN set up, such as turning on the AC before returning home or perhaps looking at the video feed of security cameras. Ideally you want a fixed IP for that, but there are workarounds.
Yeah. I’m trying to think of what I would really use it for remotely. I have reolink on my nvr which I can access with the mobile app for my security cams. I can wireguard back into my router if need to. I might not need it remotely as often as I think.