If you are using Go (which solves most of your dependency problems) and SQLite (which means you don't need to integrate with an external database via service discovery) why do you need Docker at all?
attrs classes still have several features that dataclasses don't, and likely never will, [like validators and converters](https://www.attrs.org/en/stable/why.html#data-classes). So it's not obsolete, particularly for anyone already relying on those features.
Heat pump models usually have a resistive element for use when the heat pump can't keep up, or when the climate doesn't cooperate. Then you benefit from the efficiency whenever possible. (Here in coastal CA I have mine set to only ever use the heat pump since the climate is so mild.)
The up-front cost of a heat pump is definitely an issue. IMO we should be doing instant rebates to even out the cost between the two so that it's an easy decision.
My heat pump water heater is at 140F all the time, maximizing the banked energy. There's an outboard mixing valve to reduce this to a safe temperature in the house.
Those are definitely not substitutable. In addition to the difference in glues the peer comment notes (the oak plywood will likely delaminate if exposed to moisture), you need to sheathe a house in a product rated for that use. That oak veneer doesn't have a span rating stamped on it, so any inspector would fail you.