WW from Republic is crippling.
The study of war weariness goes on. I will thank Bamspeedy and DaveMcW (any other?) for their research, it really helped. General: We measure war weariness with wwp (war weariness point). Each civ have one wwp number against each of the other civs. The different levels of war...
You might want to know how it works. If you do, then with some practice it becomes easy enough to keep WW at zero in most turns and significant in only a few turns.
Say you have 80 metros at 30% corruption in communism or as a republic you have 40 metros with 70% corruption and 40 metros with an average corruption of 30% and therefore a total average of 50% for all 80 metros. As commie you get 1.5 commerce per tile prior to corruption and 2.5 as a republic. On average it is 1.05 uncorrupted commerce as commie vs. 1.25 as a republic. Republic still wins till quite late in the game.getting me tons of corruption free production trade and science under Commie that would be far more significant than relying on my core metros as a Republic??
But the bigger advantage is of course when communism is still unavailable. In the middle age you may well research at a rate of 4 turns per tech. Having cavalry early gives you a healthy advantage on the battlefield. If circumstances allow, and on monarch they are still likely to do so, there is no (relevant) war before military tradition. This changes with cavalry. Cavalry is the game changer.
Also AI's don't like me and don't trade with me because I keep starting wars.
I spent a few weeks with an unpatched version of PTW and no internet access (to dowload the patch), so I decided to spend some of that time testing AI attitudes. This test was with the 1.01 version of PTW, so there might be a possibility that some of this was changed in a patch, but most likely...
Having AI declare war on you is much better in terms of diplomacy. You should try to mitigate declaring war and when you still do, make sure that immediately after the DoW you sign military alliances with every other civ against your enemy. This makes warfare so much more convenient. Donnot be shy to spend gtp on military alliances. Stay defensive for a few turns so that other civs take the brunt of initial action. Then wipe the rest of your enemy off the map as fast as you reasonably can. With railroads that can happen very fast.