Re: AVCs
If they are made via payroll then tax and PRSI relief will be granted at source (i.e. your tax and PRSI will be calculated on your gross less any pension contributions including AVCs).
If you make them off payroll then you need to write to Revenue and claim the tax and PRSI back yourself. I think they will process this as soon as you claim (allowing for time for them to process the claim) rather than at year end or Oct 31st.