Something to consider:
Everyone knows about the US tax incentives for buying an EV, but less considered is the incentives for buying an EV charger.
The incentives come in the form of a tax credit, up to the maximum of $7,500/$4,000 or how much you owe in taxes (pre withholdings and the like) whichever is lower. The charger credit is up to $1,000.
So, if your taxes are, say, $3,000, then it doesn’t matter if you bought a new or used EV, you’re only getting $3,000 off your taxes, and your charger credit is effectively worthless.
Consider, if practical, buying your EV towards the end of the tax year, and your charger at the beginning of the next one. You’ll minimize the inconvenience of being locked to level 1 charging speeds, while maximizing your tax credits.
Obviously, if you need a level 2 charger you shouldn’t self sabotage and should just buy one. But if you’re counting your pennies, and think you can get by with level 1 for that window, then it’s something to keep in mind.
Its not a requirement, but it's pretty common on anything in the past couple decades for the wires to be capable (maybe not a 20a breaker switch)
Not sure about the shared circuit part, but yes, don't just swap it, do the proper research, but for many people it is just as easy as swapping the outlet.