Dude, electric car's are about 25 computers on wheels. Adding a "charge between hours" function is so trivial I would be surprised if it doesn't already exist. But no, you're right, computers are a complicated pipe dream, we should all go back to coal burning, steam powered, difference engines and horseless carriages.
I own an EV and there's definitely a setting in the car to specify what time of day to charge (and my charger itself also has an app where I can specify that time restriction).
Depends, a 200amp nearly for sure has capacity. A 100amp likely does, but depends how electrified they already are, but many smaller houses that still heat with natural gas will have lots of space left in a 100 amp service
If it’s permanently installed it’s potential needs to be accounted for at all times, there is some conditionals, like ignoring AC during winter, but there’s nothing for intermittent loads, since it can still potentially be done at anytime.