There have been no risks to date with PlayStation update, unless the update was no officially issued by Sony.
PlayStation Update 2.43 is mostly directed at players in the Japan region. It does not include any features. It is not a necessary update.
While it is true that the PlayStation 3 cannot update if it is off, the playstation does not need to be continually on. If you know that an update is needed, you can turn it on, update the playstation, then turn it off. If the playstation is not downloading the update or applying the update it can be turned off. An update can't even be started without the user explicitly starting the update. Depending on your internet speed, updates can be fast (< 5 mins) or slow (hours).
You don't 'update the PSN', you update the PSP's firmware from the Settings menu on the XMB.
PlayStation Plus updates their game on the first Tuesday of the month.
most all of them, you just need to get the update that lets you play ps2 games and you get it at the playstation store
'The latest', always.
I do not get your question
you have to update your psp until you reach 5.00
yes it can as long as you update it
Perhaps there was an error, in which case you should call PlayStation Support so they can resolve the error.
No you can get Demos from the PlayStation network for free anything else requires some form of payment or risks legal penalties
Not any more since all of the hacking has been patched, especially for playstation going through a security update, I doubt if it will get hacked again