I've been meaning to move to Home Assistant for years, but most examples are like yours and I'm not sure if my seemingly simple use case is covered. Would you mind providing some additional insight?
My use case is to get off of my Alexa devices. The main feature I want is voice control of the lights. As far as which smart bulbs are supported, I'm comfortable dealing with that (I know half of mine are unsupported by Home Assistant and will need replaced). So my biggest question is, what's the easiest way to add voice support for basic control of lighting groups (ex. "Turn off the living room lights", "Turn on the bedroom", "Set the kitchen lights to 50%", etc..)? Might be nice if I could convert my existing Alexa devices into remote speaker+mics for Home Assistant, but I'm hoping there are better solutions (and hope they're affordable).
Most of the features I use are very basic Alexa features, but my normal use of them is via voice, so that has to be integrated:
* Time (What time is it? What is the today's date?)
* Timers (Set a timer for 3 minutes. Remind me in 40 minutes to get the laundry.)
* Weather (What's the weather? What's the weather tomorrow? What's the (current) temperature?)
* Music (Play White Stripes on Pandora. Pause. Resume. Set volume to 5. Raise volume. Lower volume.)
All the cool home automation features you listed are things I don't own yet. I could see adding some of those and growing my system once it's going, but I don't have any immediate need for them (apartment life plays a part there). I can't foresee myself building this out just for those sort of automations (ex. I can hear my smoke detectors from anywhere in the apartment, just look at my thermometers, have no thermostat (steam heat), etc..). But I also loathe these Alexa devices cause I can't get them to just do their job without butting in and suggesting bullshit in follow ups and ads, and I don't need all my dumb timer requests sent to the cloud just for speech-to-text.