I agree, it makes no sense to be paying an accountant and not asking questions. However, I will arm you a bit of info for the next time you talk to him so you don't feel too bad
Basically, if you are using your private vehicle you should be claiming [broken link removed]. These are dealt with in detail on the Revenue website but I'll give you a brief outline...
If you are driving 700km per week, then that averages out at 33,600 per year (over 48 weeks). Based on a vehicle over 1.5L then you should be claiming approx. €15,000 in expenses for mileage alone...
First 6,437km @ 78.32c = €5,041 approx.
Remaining 27,163km
(33,600 - 6437) @ 36.65c = €9,955 approx.
Also, [broken link removed] (meals etc) are €17.60 for between 5 and 10 hours and €43.13 for 10+ hours, so if you are only claiming €15 per day then you should be taking a little bit more there also.
With reference to your "basic wage being zero", I would not agree with this. You should at least be paying yourself minimum wage (~€18k?) so that you avoid paying any tax, but more likely you should be paying yourself €35,400 per year to avail of all your standard rate (20%) tax credits.