I have a question for the long time players. Are ranged weapons more grinding intensive because of the coatings? although I didn't quite get good with them in the demo I think it would be great to get good at ranged weapons for MP.
For bowguns you need to bring ammo and materials to combine mid-mission for more ammo, which can require additional preparation. I'm not sure if 3U will have online events where you can buy stuff en masse for cheap, but even then I prefer using bowguns for 'special occasions'. Meaning the monsters who end up being big fat slow targets when you switch to ranged. So as always I'd recommend learning multiple weapons, no reason to break the bank to gun down a Qurupeco when you can mash him to death with a melee weapon in minutes.
Bows don't use ammo but they generally take so long to kill anything that I don't bother. Kelbi bow notwithstanding, but I'll avoid that for a different reason.