"What is his viewpoint on education matters ?"
Translation:Cad é a dhearcadh ar chúrsaí oideachas?
It should be oideachais. I thought it was acceptable at first, since it follows the general genitive plural method... I guess oideachas just doesn't use genitive plural. See here for cúrsa oideachais which is cúrsaí oideachais in the plural
The word oideachas is still in the singular in this sentence so the genetive is correctly oideachais. Oideachas does not have a plural form other than a notional one...