Allow me to shed some light on the developer side of things.
I am a former developer (CGI artist). If you ever played Microsoft Flight Simultor there is a good chance you toyed with some of my work. I work in 3DS Max, Mudbox, Photoshop & Lightroom primarily.
Creating an entirely new reserve would probably be the best way to make this happen. You could then code all the ground tiles so you didnt use ammo anywhere. Its entirely realistic to have a long range rifle course. 3d archery course & even a sporting clays course on that range. From what I have seen of the game so far all the elements are already in place to make it work.
I may be talking through my hat since I dont know what engine theHunter uses but so long as it isnt archaic the mods we are suggesting shouldnt be a problem.
1st off the notion of will creating something be worthwhile to EW is frankly foolish. Every single update, addition & mod adds to the products value making the consumer that much more likely to want to spend their money on the game. Making a new map/weapon/animal is never a waste. There is always someone somewhere out there that is willing to spend money to get it. Hell there are a number of things I would love to see in game. I will even model & skin them gratis if EW will put them in game.
2nd: Unless they contract out for their talent they have CGI artists, coders, animators on the payroll. These folks need to be doing something daily to justify their salary. If they arent getting much out of them maybe they should contract out for talent ( I am available for moonlight gigs
Finally doing this is not a major project. Any CGI guy can make a good map in a day or two. Since there is already a plethora of resources for textures & animals there is very little work to skinnging the map. Hell if they wanted to they could plop these ranges down on every preserve with some excludes & flattens cutting the work down even more.
Monetizing this isnt a significant hurdle. A number of good options have already been suggested but they should avoid nickel & diming us. I like the idea of buying season passes or better yet, just make access to the range limited to members.
Frankly I think EW should stop pandering to the free to play crowd. They will never amount to much more then a blip on the bottom line. Instead make theHunter free for 2 weeks then either become a member or stop playing. There are a number of games out there that do exactly this. All of them cater to niche markets which this definitely is as well. For those of us that love it 30 something bucks a year is nothing.