Do you smoke.. ya know the good stuff.
Well, I guess I can help either way..
You've already Identified your problems, so you don't really need anyones help you just need to work on the things you've identified. If you want specific help with a certain strategy then be more specific in that regard other then that you already know your problems from the look of it.
Looking at the save I don't see anything you haven't mentioned.
1) Your military is too small, you've got maces bordering an enemy that has a stack of infantry on your border. Bad Idea, besides for the fact if someone declared on you right now you'd be screwed it also makes them more likely to declare war, have most your units forming a ring around your empire with your best units on the outside facing the enemy and just a few token defenders on the inside.
2) Cottages are better then coastal squares even with the dutch dike, looking at your capital your working coastal tiles and some forests.. Cottaging your capital is always a good idea to take advantage of Beauracracy, not sure if you were doing that but it's something to keep in mind.
3) You have cities one tile away from the coast, that is a bad idea, those tiles are completely usless if your not touching the coast to build your dike/lighthouse/whatever. If your gonna have cities near the coast try and have them touching it on atleast one square.
4) Besides for your capital all your cities are cottaged, you have no production, even if your being peaceful you need production to build defensive units/wonders.
5) It doesn't look like you've chosen your victory condition, you should have an idea of how you want to take the game on within the first few turns, remember most games are decided within the first 200 turns, possibly 300.
6) I don't like the way you've expanded, you should try and build more with your cities circling your capital as much as possible to lower maintenance.
7) It looks like your building wonders just to build wonders, if you build a wonder it should have a purpose and fit into your overall strategy, you don't need to spend 600 hammers on a wonder that isn't going to help you win when you could be spending those 600 hammers on something thats going to be game deciding.
8) You have cities in unhappiness, some in a lot of unhappiness, every unhappy person takes 2 food and doesn't do anything, think of it like this, every unhappy person you have is a scientist you could be running.
9) You can build artillery and infantry yet your military consists of archers and maceman..
10) Zara is about ten turns away from taking Rotterdam, you have spearman guarding a city with 20+ Infrantry/Cavalry sitting right by, if the AI has a stack like that outside one of your cities they are going to attack nine out of ten times.
11) You have no GP Farm.
12) Specialize your cities better.
13) I would of killed Zara and built a Forbidden Palace in his capital.
I prob would of killed everyone by now so thats prob not fair to say
Remember to

when you play.