1. If you have an out of region account and it gets compromised/stolen Sony HK will not help you get it back. Since it is locked to a HK console the overseas (EU/US) support will ask you to contact Sony HK. There is no way to get your account back.
If unauthorized purchases are made with on your account Sony HK will not refund you for them. To avoid this do not attach a CC to your account and only load up prepaid cards as and when needed. Keep a $0 balance as many local accounts are getting stolen of late.
2. Most HK PSN store DLC is now being locked to profile so It might not work on other accounts on the console.
3. If you have a US/UK version of a game DO NOT buy any DLC from the HK store as it WILL NOT work despite reassurances from the Sony HK CS people. If you call them back for a refund/reversal they will not help you and deny that they told you that the DLC is region Free.
I have had numerous PM's over the past few months related to the above issues so I decided to post this. If anyone has anything else to add to the list please let me know and I can request Shri to edit the original post.