...if nothing goes wrong with anything in the system.
Don't get me wrong, I like EVs but there is always a risk that a single cell in the pack dies or a transistor on a BMS explodes and no one want to have anything to do with it. They will sell you a full pack which is usually so expensive it totals the car. This is a pretty shitty risk dangling over second hand vehicles especially.
True but I feel if this becomes commonplace. Good luck trying to sell your cars. Your brand will be dead. Then you have refurbished batteries and third party repair companies coming into the space since as you put it, the money is the battery.
Would be amazing. At the moment I don't know of a single brand opening up batteries to fix them. They all consider them a single replaceable component/module even though inside that's far from the case.
Here is one third party company doing refurbishments
Fast chargers and higher temperatures, for example, tend to degrade batteries quicker than slower, level 2 charging and cooler temperatures.
Other rules for batteries, slower charging and discharging is best. Avoid high discharge level especially in cold. Avoid full charge when hot. Avoid fast discharge when low, and fast charge when almost full (or near 0). That 30% to 80% range, that ultra fast charging is usually limited to is best overall, but slower charging always better. Slow charging above 80% usually fine.