Correction col there are actually five type of licences.There is also HC which is heavy combination, this one comes before MC but after HR.
As with your windscreen i have heard of if you do get a truck flick up a stone they can in some instances be payed for by the truckie or the company,all you got to do is record there rego ,company details (which is written usually on the truck somewhere)and give em a call.seen this happena few times.
Jase i do feel for you when it comes to being cut off from one of these big machines , i have so a few times, but go jump in one with someone and see how easy it is to drive one,they aint that easy man, and some of them have a bad blind spots.