Took a quick look at your save. It's not that bad. I would suggest:
1. Don't automate your workers. Especially in Beijing, just build enough farms to work the mines which should be on the hills instead of windmills. Cottage the rest.
You have too many farms in a lot of cities, and you've only made 3 great people. Either use the farms to run specialists, or build cottages. As is it now, it looks like you're just creating an army of angry citizens who provide nothing.
Nanjing, Machu Picchu, and Cuzco need to have their land improved. Nanjing still has jungle. Cut that down, mine the hills, build any farms you need, cottage the rest.
2. Pay attention to your civics. You built the pyramids and you're still running Despotism! If you had more cottages, I'd switch to Universal Suffrage, but I think Police State might be best right now, since you're building military and war weariness is pretty bad.
Also, switch to bureaucracy as soon as you get Civil Service. It's a really good civic. Also a good reason to make cottages in your capital since the commerce they give gets a 50% bonus. If you're going to run Caste System, run more specialists
The best unit you can build right now is grenadiers. Build them, not musketmen. Grenadiers are way better. Also I noticed some of them have forest and hill defense promotions, I'd just stick with combat, maybe some with Pinch later when England gets gunpowder units. I don't know if you have auto-promote on, if so I'd turn it off and just give out Combat promotions.
As far as the general game goes, looks like you are in good shape to win. Either conquest, domination, or diplomatic, since you already have I think 63% of the population. I can't remember what percentage the diplomatic victory requires, but I'm sure you'll have it once you conquer your continent.
I'd suggest taking peace for 10-20 turns to regroup and build a few more units. Get a stack or two of some cannons and maybe 10 grenadiers outside Canterbury. Bust down the culture defense with the cannons and then your grenadiers will pretty much walk right in. That will take some of the culture pressure off of London. Heal up if you need to, and take the rest of the cities on your continent and then load them onto Galleons and take the last couple cities they have left. (Or vote yourself the winner in the UN)
You're off to a good start, just take care of those small problems, and you'll do great!
Edit: Grenadiers get a bonus against Riflemen, so they actually are more effective. This is probably just me, but in these ages, I usually rush to Cavalry or Grenadiers, then just use them until I get Infantry. In fact, I'm not sure I ever built a Rifleman... I guess if you're being attacked by a bunch of Cavalry they'd be good.