1. It should if they have any grandiose ideas of overtaking other massive shooters like Planet Side, Battlefield or Battlefront. Particularly amongst the casual player base. Reigning them is one thing, but keeping them loyal is another entirely
2. There should be an economic link (money and resources, as well as manufacturing when and if it is developed), there should be a corporate link, and a battle link where wars in space and on the ground affect one another
3. Yes, because it gives people a reason to fight everyday. Factional warfare and planetary warfare are the closest that Dust came to having a competitive scene, and that is what defines shooting games now. Though because the game is in the direction of an MMO the skill and dedication of a standard competitive scene like the one in Call of Duty or Overwatch are better spent in something that can affect the entire community (faction and planetary warfare)
4. The obsession is that if the game doesn't have a link to EVE then the entire point of having Dust is redundant. There are better shooting games out there by far, and this is further observed by the negative affects of the progression system. What is meant by that notion is that better equipment and abilities were unlocked through time and/or money. At the start of the games life everyone would be on par because they would start with nothing and progress more or less together. People entering the game months later would find themselves at a severe disadvantage and were often kept from having fun because their gear and abilities were not on par with those who had been playing the game longer. Therefore, the progression system was counterproductive to growing the player base over time. This rate of counterproductivity was supposed to be offset by the positive effect of enjoying a link with EVE that would allow veteran players to fight against other veterans in large scale pitched warfare, and so new players would be allowed to go under the radar and fight other new players while avoiding veteran players until the former were on par with the latter. Without the progression system, and without the link isn't Dust/Legion simply a different shade of Planetside 2?

That said, on an opinionated note, I believe it would be best to put the shooting mechanics of the game first and foremost, and develop the link afterwards. No, not as an afterthought, but merely commit to it later after the shooting mechanics are well developed. It seems that when Dust tried to coordinate both at the same time it became nearly impossible to come to a consensus despite both areas being seemingly unrelated. Though they were related because PC and FW were heavily dependent on the balance of the weapon. Therefore, an attempt at balancing the fighting elements of the game often upset the equilibrium of PC and FW. This seems to have made sense in BO2 and Overwatch, as their competitive modes were not operational until after most of the balance had already been achieved after the launch of the game. Building a project has everything to do with its foundation, and so just like a house if one attempts to lay the foundation and build the levels above it simultaneously one will almost certainly fail.

Put your flags up in the sky. And wave them side to side. Show the world where you're from. Show the world we are one.

Put your flags up in the sky. And wave them side to side. Show the world where you're from. Show the world we are one.

Put your flags up in the sky. And wave them side to side. Show the world where you're from. Show the world we are one.