I think that the advice given by Ford Cortina is sound and should be listened to. Tax law is complex enough when dealing with your home country, but combining it with income from Ireland, pensions, VAT returns, etc it gets extremly complicated. I doubt there are many people on here who can honestly state that they fully understand the tax system.
The advice I was given, and that which I will give to anyone in a similar position, is to seek as much assistance from the professionals as possible, be it financial advice, tax advice in both Ireland and the UK (or wherever you are from) and start looking to the future. I personally don't want to be in a postion in several years time where the tax man starts looking back at my history and decides that I owe money I simply havn't got! There is a very fine line between tax planning and tax evasion, and I do not wish to cross it. Prudent planning is the way forward, and if you are armed with all the information then you (hopefully) won't get a shock in a few years time.
Good luck with the type rating folks