Leaving Malta - after almost a year...

Hi everyone.

I loved living in Malta this last year - but an opportunity came up that I couldn't resist, and I'll have to leave this beautiful island in the next two months to resettle elsewhere in the EU.

On a more serious note - I have obtained a Social Security Number and a Tax and a VAT number - and also registered myself to ETC, and been waiting (as so many others) for my ID card to be issued. I also have an HSBC account.  In essence, I've done everything to become a legitimate expat in Malta.

The question is, now that I am leaving Malta... what should I do regarding all of the above?  I am guessing I will have to declare that I will no longer earn income (and be taxed for it) in Malta, but declare it to who? I will probably need to keep my TAX/VAT number, since I did have income during this year that I must declare and be taxed for - but the SSN, I should probably declare I will no longer be insured in Malta, right?  Also, the VAT/TAX number - they make sense for this first and last statement of income during 2015, but not afterwards - should I keep them and manually file empty statements each year?

Do I tell HSBC? If so, they will probably ask that I close the account, no?
(I'd like to keep it open until I at least settle in my new country and open an account there).

Any information / suggestion most welcome - I am in uncharted waters.