simple math, if they want to host 300 shooters having 25 lanes every day for 3 days in a row and 3 separate courses, you will get 4 shooters per lane. Same setup as Italy last year in my opinion, 3 different courses, now each 100 shooters (4x25) at the same time. This will take some time to complete indeed.
The benefit is that all shootes have the same conditions, as Norway had 2 groups (morning and afternoon), each have other conditions to cope with.
It will not be very crowded, don't forget, the track is a few km's long..... and a lot of steep up-down hill shooting. My friend was there in July for the German National and enjoyed it very much. Also the both German course builders from Ebern were our neigbours on the camping in Norway, so already gave a lot of info.
About the places left, I guess a lot of places will be left over a not all countries send 8 shooters, as stated already previous.