Looking forward to the guide still, but I gotta say, it took like three city attempts but I got a profitable city going and it was fun to kinda decode what the game wanted. There is a lot of information to try and make sense of, but the info IS mostly there.
For those struggling, a basic idea that worked for me when it comes to money was you rarely want an excess of anything. Lots of connectivity?? Spend it on hotels. Logistics? Spend it on factories. Each thing tends to pull on another things (factories at pollution, commercial services lose effectiveness as they outscale population, some things require professional services etcetc). If you try and "spend" all those things, you can build yourself up to profitability.
I tend to save only when I'm profitable and above a certain margin (20k). So I'll try to expand, and if things go bad because I'll trigger a cascade of needs I can't fulfill on my budget, but then I understand the tradeoffs better.
Also don't be afraid to demolish stuff to upgrade it. Bigger, later unlocked buildings tend to be more efficient (TEND) so redoing buildings can cut down on the tiny inefficiencies that are killing your city. Also don't worry about running a deficit in some stats. It seems to vary between stat, but usually as long as the deficit is under 10% it's not too bad. A labor deficit can be much much better than building a bunch of new housing that then requires more electricity and water.
8 days ago(+1)
Also lemme post my city, 200+ years in, since not a lot of people are sharing. Off in the corner is a nuclear power plant and a few more high tech industry buildings.