Here's the map:
2380: Rearranged some sliders, sent a scout to the purple behind the Humans, and shuffled some pop around. Dialed back the Planetology spending, reducing to 13% from 14 to open computers. I put 2 clicks into spies for all races, I want to peek at what they have to decide who our first target will be. Draconis and Cryslon set to build colony ships.
2381: IT+20 arrives, IT+30 only choice...it's level 14 so I close out Planetology tech. Only choice for comps is ECM1. I move some of the tech into Constr. and FF to get those going. Tech spending takes a hit as terraforming projects take up much of the empire's production.
2382: Shuffle production as Terraforming finishes on some worlds. Some back to tech, some to build factories for new max. Stalaz is back to making popguns.
2383: Spies penetrate the Human Empire.
Humans: No hostile techs, only range 4 available. Practically this means that Dunatis, Terran 115 is the only world that the Humans can land on of ours. I send a few more popguns there, and start building a base.
2384: ECM1 is found, RC3 is only choice (our last computer tech). We are really going to need to steal some battle computers.
Darlock spy penetration. They have Range 6, no hostile techs, and Fusion bombs. The Humans look like a more tempting target. Romulas is most vulnerable to Darlock attack--only 3 parsecs and Minimal. Since it's got max factories for its current pop, a defense base is started. Darlocks also have range to Cryslon and Draconis, but I don't expect them to attack when their only fuel base is Yarrow, and it doesn't have any bases yet.
2385: Spot a scary looking Human fleet near Dunatis. I push up spending on bases there.
Bulrathi: They have Range 5, Barren, but no weapons or engines. They cannot land on Primordius or Rha, so Lyae is the only worry. I reinforce it with most of the popguns from Rha.
I think that the Humans are our best bet for first target. Take them out before they make contact and diplomatic ties (Buls are allied with Brains). They also have BC2 and 3, which we need, and have just gotten Warp3 engines. We can also pick up Hand Lasers and Pellet Guns, which will come in handy against everyone else. We will need to wait for Hyper-X to come in to be able to start building an offensive fleet. Our popguns won't scratch their bases, but Hyper-X boats will do decent damage. Add in Ion Cannons or stolen pellet guns, and we should be able to handle their fleet as well.
2386: Colony ship finished, sent to Toxic Arietis. Cryslon will finish Colony ship for the final planet (Jungle in SW corner in 2 years). Spies penetrate both the Alkari and Psilons.
Alkari: They are lacking in comps and weapons, but those Battle Suits are a prime target. Too bad our spies can't steal that Tech Level 11 gem. Altair is 6 parsecs from our nearest colony, and they only have range 5. I go ahead and assign our spies to attempt to steal from them. That scanner would come in handy to see any agression coming our way.
Psilon: Typical brainiacs, although they don't have as much computer tech as I expected. They also have Hand Lasers + Duralloy + PDS, so ground assaults will be messy until we catch up a little.
Looking at all the races, I still think that Humans should be our first target. They are isolated, so we won't have other races trying to poach our new aquisitions. The rest of the races have a very limited selection of non-hostile planets of ours to target, which means they are just as likely to attack each other (esp. the Darlocks). The Humans are going to attack us no matter what, because they have no other options. They also have some nice tech for us to absorb, that will help with the rest of the races. BCs, IS, Sub-Lights, Hand Lasers and NPGs will all help us put together a better fleet.
My plan is to wait for the Hyper-X (2% now) and Duralloy - will push some of the weapon tech there after Hyper-X come in. Then start putting together a fleet of Hyper-X boats to take on the Humans. I really hope we can hit them before they get planetary shields. In the meantime, I am trying to get all of our colonies stood up, and build defenses at the habitable worlds along our borders.
2387: Next turn
2388: Colony ship built and sent to Jungle SW. Herculis founded. Pop sent from Vox and Volantis, can be redistributed to the new colonies when they are founded.
2389: next turn
2390: next turn
2391: Hyper-X arrive. Ion Cannons next. I debated on the Fusion bombs, but they aren't very effective until engines and weapons are upgraded to a point where they fit in a small, fast bomber. Ion cannons will help us take on the other fleets. Bulrathi don't like how big we've grown.
2392: Toxic Arietis founded. Will shuffle pop from Herculis when they arrive next turn.
2393: The purple star behind the Human Empire is a no planets system. Ouch! We draw the mineral depletion event, and it hits Stalaz. A radiated rich turns into a radiated poor.
2394: Spica (Jungle SW) founded. Pop sent from Herculis. Duralloy armor comes in, Construction research is now closed. Split budget between weapons, comps and force fields. Design two missile boats. Production of Guppies is begun at several places, and Cryslon works on Flounders (main function is to bring along the battle scanner, but also meant for finishing off any leftovers of enemy fleets after the missile barrage).
2395: FF2 comes in. FF3 is only choice--no PDS

Minimal spending continued in FF, as there are many ways to steal/acquire FF3. RC3 is into %.
2396: RC3 comes in. Computer tech is now closed. Focus now on weapons. Bears have a fleet inbound to Primordius (or maybe Lyae, can't tell when they move so slow...) They'll meet over 100 Minnows and a missile base when they arrive.
2397: Never mind, the Bears are actually going to Rha. Fleet redirected. Factories are popping up all over the empire.
2398: Rha should have a base up in time, along with lots of Minnows.
2399: Battle!

Bulrathis vs. 128 Minnows and 1 missile base. We lost 19 Minnows, no survivors for the Bulrathi.
2400: Scout probes Human Phantos. 75 pop and 14 bases. Vote: We have 11 of 28 votes giving us over 1/3. The Humans and Psilons both call to express their reluctance to be assimilated.
Wrap-up: I took Dunatis off factories. This leaves 35 pop unemployed to use for ground assaults on the Humans. There is already a respectable fleet staged at Dunatis. Kailis is probably the best target--it's closest and has only 9 bases, but scouts will hit the other Human colonies next turn to probe their defenses.
The Bulrathi are down to a tiny fleet. However, attacking them is probably not wise. One snag is that they don't have any useful techs to acquire, then there's the ground fighting against Giant Bears. The three colonies of ours near Bulrathi space haven't matured yet, so they're not the best places to tap for vast amounts of troops. And if we did wrest one of their worlds from them, the Brains would undoubtedly jump in to try to take it for themselves. At this point, I don't think we can compete with the Brain fleet. I still favor taking the Humans out. We'll get a good amount of useful tech from it, and we don't have to worry about the other races jumping all over our new acquisitions.
Once we have a better fleet to back us up, I'd love to take one of the Bulrathi worlds...then let the Psilons take it from us...and then take it back from them before they get any bases built. If enough factories survive the various invasions, we could wind up acquiring some nice Brainiac tech without having to face their missile bases.
Force fields: I have a minimal investment in FF3 research. We could skip that and just pick it up from our Human campaign instead.
Once we have finished researching weapons, we'll have an interesting situation where we can focus 100% of our production on our war machine...no pollution to clean up, no research to do

I'd recommend setting up some of the larger, more hospitable worlds as troop centers. Put them on 100% eco spending, and shuttle troops off towards our front-line worlds. That way, we can co-ordinate our assaults from the closest planets, and have pop coming in to back-fill them for the next assault. That should be better than trying to coordinate with troop transports needing 10+ turns to arrive on target.
We are done with Colony ships now (unless we kill the Guardian), now it's time to turn

into
Resistance is futile. You will be assimilated.
I saved the game as both save3 and save4 and zipped them together. I thought the norm was save3, but I got save4 from Liq, so I give the next emperor his choice.