Re: Claming tax back
As a rule of thumb, I think the revenue will generally give tax rebates at the lower (20%) rate on prescribed items - check out their webiste, it is pretty comprehensive. Try get the email address of the area tyou're allocated to - getting through on the phone is a night mare.
Some expenses also have an excess, for example with medical expenses you're expected to cover the first €125 as a single person (€250 married), the reset is claimable at 20%. I've had rebates for glasses, they will give you a rebate for sight testing and some toawrds the lenses / frames (not much, but it's nice to get something back after paying all those taxes). They don't cover everything, so check out their website.
I've found the revenue pretty good for college fee refunds (they cover all colleges within the EU, the latest rebate was from a course I'm doing by distance learning in the UK). I've done a few here as well and generally had a cheque within a few weeks of claiming. Form IT31 is used for this, avaiable for revenue website.