I have a few problems with your tipps.
1. If your pop stays at 1, you won´t be able to build a settler.
2. Stonehenge for your policies: What if the AI builds it first?
3. Your choice of policies is fine, although I do not take monarchy. Only if a very food heavy capital. On the other hand: their is no fixed policy choice. If play Songhai, Germany or Ottomans I go for honor for example.
4. Water Mills are a must for me. 2 Gold for +1 Pop and +1 hammer is always worth it.
5. Happiness buildings: 4 Happiness resources and then having surplus? Not in my games. After a conquering spree 4 resources are only a drop on the hot stone. To make a calculation: A happiness building is 2 gold for 3 pop. Again: always worth it.
My personal list for infrastructure (early game, late game just buy what you need)
Monument (Not if I am about to get Legalism)
Watermill (if possible)
And then depending what the city needs. Sooner or later all buildings without maintenance are built.
I should have noted that strategy has some guidlines that must be met. It needs to be a standard or larger map on a harder level 6,7,8, not archipelago. I only do this at the start in the capital, never the next cities. Gems, gold, or silver on a hill is a must. China gets a starting bonus for this, they'll usually have a lux on a hill not always but more often than not, some other civs have this bonus as well. IMO china is the best civ in the game.
The settler thing is nbd, a +1 population from a ruin will let you build it. The idea is to spit the scouts and worker and warrior out quickly while the AI is city spamming. They are so far ahead to start on the hard levels it evens the score quickly. we know we can't spam cities faster than the AI on hard levels while keeping infrastructure. This also keeps your own population down in the early game helping happiness. AI also stays off your back a while early on if theres about 4+ ground units and you're not spamming cities or making friends. My idea is the minimum amount of population with the most production and gold wins the early game. Monuments are a waste of build time, legalism gives you 4 free ones, which the core cities shouldn't be much more than 4 unless a larger map. Then the route of landed elite, which helps greatly for production based early game cities.
Once the worker, one or two scouts, and warrior are out its a good idea to start thinking about moving that 1 citizen to food if you haven't got a +1 population ruin. Rapid exploration is the key. Low populations, river tiles with woods are good too. hills are best.
The AI doesn't build stonehenge first. They build great lighthouse, library, colossus, hanging gardens, oracle. There's only been one game I've yet played they build stonehenge before one of those. Calendar should be one of the first few things researched for luxuries and at that time if production is up shove out that first settler and go for stonehenge. I usually end up buying the first settler. trade double luxuries for gold and trade open borders for gold to get a research agreement with someone who has philosophy till its researched.
I personally don't get the honor social policy column. A country with a higher great general spawning bonus - china, or greece's calvary, or a few other units, will do wonders for the military. China's great general spawns very fast and also has the 10% extra bonus, so its like having the first two honor policies anyway. unless hunting barbs for gold with songhai.
Monarchy - by the time its reached the capital should be around 6 population, its good for 3-4 happiness and a few GPT for free. extra happiness holds the civilization over until theocracy. After those policies, whatever is needed. If this is done, a population that is in check with lots of luxury, production, and gold will not need happiness buildings until military conquest. If happiness bldngs are needed before warring then something isn't right, too many people or cities too fast, not enough luxury or trading or social policies that are doing something else
I will sometimes get the liberty column and the free worker and a free great engineer from meritocracy, then plant the engineer for +5 production in my capital's tiles...only if my happiness seems like it will hold me a while, if there's happiness troubles then I go straight for theocracy. I never get anything but meritocracy off the liberty one, its on to theocracy, or merchant navy if 2+ of my core cities are coastal.
large inefficient populations and city placement hurt happiness. A second very quick early city hurts happiness and gold and are harder to defend against barbs, and makes AI more aggresive. I never let the governor take over till the later game when its basically won already, around early modern era. production and happiness win the game in that order on difficult levels. Buildings that make happiness take away from production buildings, military production, and gold(science). Since gold is science, a no-maintenance science building that gives extra gold makes science even better - again china.
The #1 must have building for harder levels is workshop
Happiness should be in check before conquest, 5-10 is probably minimum, a standing military that you know can beat the next civ is all thats needed, then during the conquest after you know the AI is beat and happiness goes in the red and you get more GPT, build happy bldngs at leisure. Happy bldngs before war is no good, takes away from gold supply to upgrade or buy units when starting military campaign.
... just for reference by doing this I usually pump out the cho-ku-nu during the medeival era in 2-3 turns in capital and 3-4 turns in other cities.