Lots of impressions zero clicks

Depends on what you call large number of impressions really, being in position 10 would not gain many clicks. From research I did a while ago now Position 10 gains just 2.6% of clicks. So if you're getting 100 impressions I would not expect to see more than 2 clicks. 

As for the position shown, Yes this is something that confuses most people. You have to bear in mind it is the average position for everyone searching that keyword. Now seeing as everyone gets different results depending on their location/search history etc then it is not surprised your experience does not match. 

The one thing you can look at though is your page title and meta description. This is what appears typically in results, (not always) but does it encourage the users to click your page over the others listed. Sometimes really slight tweaks in this area can improve clicks drastically. 

I agree with Chedders, this may be normal for positions 8-10.  I have seen a jump in clicks when a page moves from 2nd page to first page (1-10th position).

What you should be more worried is if you had a very low conversion rate when a visitor actually visits your page. 

Try changing the description to a more attractive one. So that it contains a call to action. Compare meta tags with competitors and make your field more attractive