Nice!

You are finally trying as Byzantine. By the way the map looks you are doing well.
Some observations:
- In my games Russia is always struggling against the Golden Horde and Poland. It became a rule really and I do not count on it pass Volga.
- I always try to annex the provinces at a rate compatible with my rep. Otherwise I waste a LOT on wars I do not want to win.
Here's a pic of my old game:
You probably saw it before. Here's what I did to start with (and keep a good rep).
1. Sign alliance with Georgia or any other Orthodox state for that comiong war with the Ottomans.
2. Declare war on Maltese Knights and conquer them. Annex the island. Sure your reputation will drop, but Byzantine can afford it as: the province is a national one and rep goes up if your national proinces are owned by somebody else and Byzantine has a lot of that.
3. Fight that war with the Ottomans (I'm sure they will declare war between 1419 and 1420). With 2 allies (or more if your diplomats are good) the Ottomans are beatable. Do not take any land from them or take 1-2 provinces. You need that rep for other places. A good peace treaty without loosing your provinces (Moria or Rhodes) is sufficient.
4. Using your ally Trapezund declare war on the nation that holds Armenia. Win and annex it. You will connect a land bridge to it later.
5. Now you could get Cyprus since it is still an independant state. Sure you have a drop of rep, but if you were not greedy you could afford it.
6. The hint from now on is to win occasional 1-3 proinces from the Ottomans, keep them in check (i.e. from getting bigger than you) and keep expanding your empire at the rate compatible with your reputation.
7. Now if you noticed all 3 "initial" provinces: Rhodes, Cyprus and Moria you have wine. Takes a little time to get to the level where you can build Wine manufactures. With gold in Armenia and 3 manufactures you'll have a lot of gold for future conquests.
In this manner my reputation never went below "poor" or "bad" at some point. By 1700 I unified the Empire with every province having at least 3 level citadel, a manufacture and being Orthodox (except for Cairo cuz thats a pain).
Anyway thats my game
