I am very iffy with forums so I am on and off alot due to life. Please forgive the long wait for a reply.
If working together was the most functional path to humanities success it is most likely that we would all of been working together ages ago, it follows the idea that ultimately what humans are only really after is output and production capacity-be it for science or material wealth- where basically our entire struggle philosophically, religiously and politically is that we crave more than simply doing well. Everyone wants to do well but we all want to well on our terms. There is no paradise, there is no unity, there is no collective.
No. Organic life has done well due to a struggle system and intellectual life will prosper due to a brutal intellectual arena based on the same scrutiny. The lazy cynics and the unstructured dreamer must be dragged out from all their beliefs, philosophies, political subsets and ideas, nothing does this better than opposition. We are all the poison in the well, we are all the homeostasis(water self cleaning process)
Yeah, it sucks...but you know. Life is full of hard truths. You can either headbutt the rock or work with it and create something useful or artistic like a statue.
Although you could say that technically science serves the common interest and thanks to stuff like the internet that allows information to be transferred across nations in seconds that we are inadvertently aiding one another in our technological growth.
2:
Hard to say, I mean at the point when a species has reached a 4 or 5 on the scale as far as we are concerned they are god like in comparison to our current perception of the universe. If a creature is of such vast intellect and power it may be they are totally incomprehensible to the human world view due to the reason that
1: They are alien and there go already present a barrier of general understanding
2: they are highly evolved aliens whom could even be post versions of their own race, even further increasing their gap between our species
3: they understand and witness so much of the universe that we can't measure or perceive what their reasoning may be. If they are able to move from our world into other forms of realities, even perhaps into other phases of existences we are unaware of at this time that they no longer adhere to anything that can count as logical or reasonable as those ideas would not do them any good in another reality where such logic and reason are non-applicable.
4: We don't know their culture, philosophy or religious values if they have any or their physiological states. For all we know they could be Borg Bugs with no sense of self, super ego or real ethical or philosophical disputes and growth but seem so alien we can't identify their lack of these things.
So....why?
Who knows. It's possible that if existences are linked humanity may have a bigger unaware effect and it attracts their attention, maybe they are bored, maybe they are hungry, maybe they like to establish dominance, maybe they want the world or to preemptively get on a growing races good side. Maybe they are friendly and just want to see all intelligent life be able to cross the stars.
or....you know...they could be so advanced that we are already under their control without even realizing it.
None the less, pretty fun to imagine one way or another.