Your PSN account profile should work across any Sony device that uses PSN.
yes
Having a PSN account lets you access PSN services on various Sony consoles. You can use it to purchase and download games, rent movies or play demos.
no, your online rank will only be deleted if you delete your xbox live/psn account.
Technically yes you can. Your PSN account is a Sony-wide service regardless of the device you are using it on. You can redeem a PS3 code while on the PSVita's own PSN 'app', and it will be added to your PSN account. However of course, that will not let you use the PS3 content on the PSVita.
No, a Japanese PSN account can only be funded with a Japanese PSN card, one with a yen amount on it.
PSN only accept Credit Card or Debit Card that belongs to the region in which the PSN account was created. If you have a US PSN account then you can use only US credit or debit card.This is because PSN does some background check called Address verification Check which is basically Sony checking with your card issuing bank about the address, if the address is from a different region then you will not be able to use that card for that account.Other alternative is to use PSN cards. If you are from a different region and you use a different region PSN account then the best option is to buy a PSN card online.More detail on this can be found at : http://invisibleknight.blogspot.com/2013/04/psn-cards-playstation-network-cards-how.html
by PSN you need a account to PSN
how can delete no frm sony ericcson
They don't delete, the account get banned and there are quite a number of reasons. If you read the related list you may find you have been doing many things that could get you banned
No you can't, PSN cards are country and currency locked. You cannot redeem German PSN topup cards on a UK PSN account.
To access the Japanese PSN, you need to register an account on PC, on the Japanese PSN site, and connect to the PSN on the PSP with that account.