The ringworld has a modifier which gives enough resources to cover upkeep on the first of each section after you build it, and a set of blockers that when cleared give you the rare resources to build one of each section. If you have multiple of a single type of section then you'll need to get the resources elsewhere, but by that point your economy should be strong enough that you can buy them off the market (or have income from elsewhere, especially since your tech will be so strong).
I'm giving this a try now, and it's just like you say. There are blockers which give you enough strategic resources to build one of each district type, and the Arcane Generator step in to provide the upkeep for one of each district type once it exists.
Which means your capital segment is going to be a bit... unoptimal, if you want to use the generator to the fullest extent (all for types plus an extra you pay for). But since it's the capital it can't be specialized, so that's pretty okay.
I'm playing that Ithkul (MoO3) Devouring Swarm race I mentioned earlier, and I way overexpanded and am suffering the consequences. It's 2221 and I haven't built a research center or district yet, trying desperately to maintain military parity with my neighbors (one of whom is fanatic militarist to be fair (Couldn't be an Inward Perfect could it, huh? Just Militarists all day erry day, but thanks for making them xenophile I guess)).
This might be true for all Ringworld Origin, but I'm having to manually juggle pops a lot with the crappy "place a limit on this job" ""priority"" system. The actual system for assigning priority is nigh-useless, except for enabling it for maintenance drones on every world because... I have no idea what the conditions are for drones to actually work those jobs, but a painful amenities deficit doesn't do it.
Still astounded that Ringworld-start civs get a habitable planet type though. I had so much fun with Voidborne that I sorta assumed they were like Life Seeded, unable to live on normal worlds without significant penalties. I suppose that would be a lot rougher than Voidborne, since you can't exactly build more ringworlds early game.
...except you *can*, refurbishing the abandoned segments for another 60-100 some pops.
But I get it. Being isolated to one "world" would be a massive handicap.
Because pop growth in Stellaris makes NO SENSE, it's (if anything) REVERSE EXPONENTIAL as worlds with a few people reproduce FASTER, AAGGH