While I forgot to mention it I think I actually had lv4 tax and lv2 production everywhere and I'd say - Temples are fine and the first 2 production buildings but after that - don't bother.
Contrary to what the others are saying my experience with every nation I've played is
Trade income > Production income >>>>>>>> Tax Income (totally irrelevant)
I have had production income outstrip trade as nations in Africa and in India, when not picking trade ideas. Trade ideas + concentration of light ships in a strong node = big trade income almost anywhere, and most nations either begin with or can conquer a strong node pretty early on. Trade ideas + good conquest target brings in the most wealth in most cases.
As for buildings:
Temple: Pretty good everywhere, especially if you have NIs that boost FL as with offensive/quantity you'll get 17 FL from 40 temples then, in addition to the money.
Rest of government path: Very situational. Good in your capitol, as the +spy defense works on most non-claim diplo actions and you have a tax boost there anyway. Also good in provinces like Rome with a ton of tax because the finisher gives 3% missionary strength, and the Papal State will almost certainly have it all built for you (so you only need Cathedral when you take it).
Army: You can really jack up manpower and FL and it stacks amazingly well with offensive/quantity (20 provinces with this line would give a whopping 68 FL, meaning in 20 1 tax provinces full army + temples would give over 80 FL haha), but in SP this tends to come roughly when you don't need it anymore, often much after you don't need it anymore. Pretty good for stuff like Sunset Invasion in provinces where you don't have anything more important to build since even with the junky 1.7 new world tax you could get FL well over 500 with gobs of manpower with heavy investment here.
Navy: Not a strong draw in SP, but you can jack up your naval FL a bit. Naval powers can go nuts with maritime/quantity/exploration.
Production: Put the full line in gold provinces; the 6th building adds 20.00 by itself. Put up to production 4 in a few provinces where you train troops, because -20% regiment cost also applies a -maintenance cost to the units trained from there. Build up to level 2 if the trade good is pretty strong.
Trade: Not bad in general and definitely to level 6 in CoT/sound tolls/estuaries.
Fort: Good for borders in terrible supply like Russia, for a little help converting Rome, or for late game wars vs AI if you just don't feel like dealing with that front, not so great otherwise.
For Muscovy, getting into a better node is pretty useful. With their NI temples are even more attractive than usual (they're a good value building early on), after that you probably want to lean mostly on trade, production, and manufactories. Controlling an end node and the entire path to it isn't realistic (well it is, but not during the time period where you care about your income), but as long as you don't go 1 iteration from idiot Wien and its HRE prince trade idea spam you can probably make pretty good bank on trade.
