I don't really know what Bahaivision is like. I just know that they keep talking about big government.
And the one big government that I see (the UN) is corrupt as hell. Rape, child abuse, collusion in the ivory trade (they have this nice ivory sculpture that they never got rid of), a real fiasco in Rwanda, buying up land for mysterious purposes, having people on the human rights council that shouldn't be there and are just using it as a shield. Oh yeah, and their climate change proposal would basically send most countries back to the stone age, while India and China don't adjust anything, and it would maybe adjust the temperature a hundredth of a degree if they bankrupted themselves for years. This is the UN plan, not the Bahai plan (I'm creeped out by Bahai too, but the UN has a literal map of the world in ten regions):
If anyone has read Revelation, and a mention about a beast with 10 horns, this ought to creep you out immediately.
Basically, this is why whether belief in world government is deceit or idealism, from what we have already seen of such government in unofficial world governments, I am not hopeful. I don't believe that even the most well-intentioned people can make an ideal, and deluded or outright evil people are more likely to take that position. Sorta a mix of power corrupts (absolutely) and what they taught me in Habitat for humanity. To paraphrase, unless God builds it, it's not gonna work.
My vision would be a loose set of nations in trade alliance with no larger delusions of state rule. In fact, I wrote a book (in the Literature section) where there was a Council, and the first thing this (slightly hypocritical) organization did was preventing big centalized organizations such empires or world leadership groups (even though they WERE a world leadership group ^_^ ). We don't need one group or one person to bring us peace, we need a sword to create national boundaries and keep them from being empires.