Is there anything in continuity that states the founders are limited to the big 4?
Arbaza was a founding member of the Federation, according to Starfleet: Year One. Ithenites were speculated by fans for years to have founded the Federation. The Violeceans may have also founded the Federations, as they too, like the Ithenites, are seen in “Journey to Babel”.
According to Star Charts, the Catullans joined the Federation in 2185. But in TOS, specifically in “The Way To Eden”, the Catullans are applying for Federation membership. It could be possible that the Catullans joined the Federation, and then withdrew from the Federation. Maybe they’ve done this several times.
Starfleet: Year One has Dedderac, Vobilites, Osadjani, Anjyyla as early Federation members.
Coridan never joined the Federation, despite their government once being under the influence of Vulcans, and rebel factions being backed by the Andorians.
Rigel joins the Federation early on, though it might have been staggered and occur over several years, with each habitable world in the Rigel system joining on their own terms.
Might we squeeze in another war?
Beta canon has the Tarn War occur within the first year of the Federation's founding.
It makes sense to presume that there was a Xindi civil war that the Federation tried to mediate. Or a resumption of hostilities between members of the Federation and the Xindi, since there never was a peace treaty signed. It makes just as much sense that the Xindi founded a counter-Federation of their own with their neighbours in the Delphic Expanse (Illyrians, Skagaraans, Haradan, Ikaaran, Kovalaans, Triannon remnants, etc).
A space version of the Barbary Wars also make sense. Obvious participants would be the Orions, Mazarites, and Osaarians. Less obvious participants would be in Andorians, Tellarites, Romulans (labeled ‘pirates’ as a cover story), Klingons disguised as other species, and humans (artifact traders on the black market). Or the Eska hunting cosmozoans.
Early 23rd century would have the Tholian expansion programs.
We don't know when contact was made with the Trill and Betazoids. Were they around since the beginning? Joined shortly after?
The Trills and the Vulcans have an antagonistic history, more than humans and Vulcans did, that resulted in a xenophobic Trill government. Vulcans made first contact with Trills eight years before they had first contact with Earth. It’s not known as to when humans first met Trills. Or Betazoids for that matter.
Deltans? Did all Earth (and non-human) colonies immediately join or be included at formation or did they need to join separately?
According to MA, Earth traded with Draylax, both Teneebian moons, Trillius Prime (which is possibly a different world from Trill), Proxima Colony, Vega colony, Deneva colony, the Demerians and possibly the Orions. That last one is an unknown as Tellarite oppose trade with the Orions altogether. And not even counting the Federation establishing colonies like Izar and Wrigley’s Pleasure Planet. Or trade with the pre-warp capable Deltans.
Earth have been familiar with the flying parasites from "Operation--Annihilate!"and the relocation of the inhabitants across Beta Portolan, Levinius V, Theta Cygni XII, Ingraham B, and Deneva.
Denobula traded with Earth, Fellebia, Neethia, Pree', Pyrithia, and Vulcan. But their membership is a mystery becuase of their use of genetic engineering and Federation banning that technology.
When was Babel established as a neutral diplomatic location and why?
Isn't Babel a codename?
The Kzinti wars especially feel like one of those pieces that doesn’t fit neatly into the “big 4” story.
It’s fair to suggest that the Kzinti scavenge post-atomic wastelands. Presuming that those worlds do not have warp drive. It explains their wars with Earth before Earth develops warp drive and drives them away.
And there has to be plenty of them, post-Romulan War. I figure that since United Earth embassies are considered to be Earth soil, maybe the Romulan Empire bombarded/nuked those embassies across various allied worlds. It does make me wonder if or how badly they attacked ShiKahr, considering the matter of reunification.
The point that was always strange for me is the nations of Andoria and Vulkan (no idea about the Tellar) pre the federation they had not really a big fleet as far i know. Well i never seen a real Vulkan or Andoria fleet. They didnt colonize much. How many Vulcan and Andoria planets you can tell from? They had the technology and they are competent and Smart people..well ok maybe they like to be more isolated from the rest of space. But if i would be a leader of an Alien empire like Romulans, Klingon aso. They could easy conquer them and take thier technology for themself. As for the Vulkans: would it not be logic to build a defence fleet to protect thier homes from intruders? Colonize more planets so if one gets lost the culture stays alife?
My question is. How could they surwive so long without the allies from the federation.
Through their trade routes and neocolonialism.
Vulcan has trade routes with Altair, Arcturus, Cor Caroli, Coridan, the Deneb system, Denobula Triaxa, Kaferia, Lorillia, P'Jem, and Rigel. They are also close to Risa, the Regulans and the Agaron government. And various allies from the Interspecies Medical Exchange – Dekendi, Mazarites, Tiburonians and humans.
Andoria has or had the Arkenites as a subject species. And interests on Coridan. Also, Valakis is located in the Andorian sector, so they may have had dealings with the Valakians and the Menk. Andorians were also familiar with the Deltans, according to beta canon.
