This kind of stuff got legalised in Germany: Banks said that e.g. Sofortüberweisung was instigating their customers to break their TOS and should be shut down, anti-trust then said “nuh-uh you can’t just shut down legitimate business” (Sofort is indeed legitimate) and instead put third-party systems under banking regulations, and required ordinary banks to have APIs allowing third parties do do sensible things.
…which theoretically could mean that you’re sent to your actual bank to authorise and thus getting rid of the normalising phishing problem, dunno, haven’t checked I’m boycotting them out of principle for going down that route in the first place. Don’t serve any purpose now that we have real-time transfers, anyway.
Yes in principle to male plug, no to 240V unless the inverter sees a frequency to sync to. They won’t power anything during a power outage that requires the whole electrical installation to be set up for it so you don’t leak power to the outside and fry a lineman. Also that inverter attaches to one phase only which means that its power won’t even reach 2/3rds of your circuits. It does make the power meter go backwards though which is the point.
That said, ideally you’re using Wieland plugs and not Schuko so you won’t have exposed prongs. The VDE certified Schuko for feeding in up to 800W though and that’s exactly the amount parliament said doesn’t require a permit or even talking to your utility. If you’re doing everything new going with Wieland is the sane choice those outlets don’t cost a fortune, if it’s an existing installation though a) your landlord might not like it and b) electricians will demand more in travel costs than the outlet is worth.