You could try this. Build akkan and keep you fleet supply not upgraded and fill up slots with cobalts. Skip planets to get to choke points colonize them and Star base them all.
I think it would be better to go 2-way colonization. Build an Akkan and get chokepoints, and first frigate should be colony ship and some cobalts (like 5-10) and the protev should be accompanied by the cobalts and take the easy asteroids and dwarf planets around you, these will improve your early economy by a huge amount. Skipping these is not a really good idea, the extra resources help immeasurably in setting up defenses on the borders. But never forget to upgrade the population to lose the underdevelopment, and build all extractors, after several years I still manage to forget these too often
BUT never bring in your protev until most militia has been cleared, not a clever idea to lose an expensive colony ship early game.
If your startes is not an Akkan (so you want to get the Marza level6 ability as fast as you can), you can still do the 2-way colonization, just build 2 protevs, the Marza has so huge firepower it will easily clear most worlds fast and meanwhile get some nice levels.
So, 2 smaller colonization fleet is the best, Akkan alone can deal with most planets (though the heavily defended terran and desert worlds with several heavy cruisers shoud be avoided unless you have frigate escorts.), and the protev+cobalt fleet will easily take easy worlds (asteroids, dwarfs, lightly defended ice and volcanic planets).
Remember, it is just Normal AI, it does not get resource cheat like Hard does, so if you take more than 50% of the map in a 1v1 you are winner, though smaller territory is more than enough because AI likes to waste tremendous recources by attacking starbases with miserable fleets and lose them all without dealing real damage to you. And the AI never goes trade-heavy, so if you do, he will be in a huge disadvantage.
A starbase with only a capital ship to help is able to fend off an attacking early-mid game AI fleet, I tried it myself many times, if you have repair you don't even have to build a huge fleet to easily contain AI, and if you place some turrets next to the starbase, it will help much. Hangar bases should be ignored unless you have their special abilities that are awesome for all races. I usually have a moderately upgraded starbase, 1-2 repair bays and 1-3 turrets next to the starbase, and expand defenses only if needed. If the AI starts to birng anti-structure cruisers, build corvettes fast and snipe those ships, his losses will be significant while you only lose some cheap ships.
I dont want to sound negative but ummm i was watching one of my mentees play 1v1 vs AI last night and he had 82 credits/s at 32 minutes. I dont know how the game changes 1v1v1 but just having like 1 trade port on each planet in a trade line would give you like 40+s or 50+s without much expenditure on your part as you dont even need extra labs ( assuming you make at least 2 civs labs for planet colonization research). I still think you waste too much on useless research.
It is not impossible to go eco-heavy against AI this early, but you need to know exactly what you are doing and what you can allow yourself to do, it is very hard, like walking on a razor's edge, one mistake and you may lose too much. But if you can set up a nice eco early, well, the AI is in a big trouble 
What level AI was it? And was the AI attacking him early?
Also, the impact of income depends on game speed... So 30 can be huge if he is playing on Normal speed, while 40 is just meh on faster settings.