"Once a Sony Entertainment Network account is created, you can not delete it. It will remain on the PlayStation Network servers forever. If you wish, you may remove it from your PlayStation®3 computer entertainment system so it is no longer visible." see related link
They have a procedure for removing a Sony Entertainment Network Account. The following has been copied from related link"
Please note that if you delete a user, all game save data earned under this user will be deleted as well, be sure to copy any game saves you wish to keep to another user.
Yes you can create a Playstation Network (PSN) account without charge and except for your own internet service provider there are no charges to use the PSN
No they are downloads that must be done with Playstation Home but not for just to get to the Playstation Network. There is of course space taken up in you PS3 harddrive as files are created including the account information. There could be what is called a download each time you get information like your trophies status, but you do not download the Playstation Network and instead download the information needed.
No because you need a router to connect to the playstation network
Yes. PlayStation Network allows you to save your billing info (ie. a credit card) to your account, allowing you to buy games on the PlayStation Store on the PlayStation 3 and PlayStation Vita without the need for a prepaid card.
You can't.
you should get to make a account without deleting you other
Sorry But It's Impossible.
Yes, you can't do anything really on the PSN unless you have an account. The biggest reason is so you can register your Sony consoles to it, to allow them to access whatever PSN content you purchase.
Playstation Network Cards are not free and do not use virtual money but actual money
You can't cancel a Runescape account without a password, this is to prevent random players from deleting other players accounts.
Go to Account Settings Choose Security option from extreme left Choose "Deactivate your account" at bottom.
Games are linked to the PSN account so that's not possible.