One thing you must understand is that no matter your faction Bandits and Bribing vital to your success.
This is NOT a normal Wargame, neither are the people you are fighting and yourself normal professional armies.
Bandits should mostly be used as a Garrison Force going around buying Collies (with the 10$ option to increase the support of the Peasants and the misspelling is to avoid it getting censored) and putting down Rebellions.I know it sounds Paradoxical but if you pay them about every 2 weeks they won't loot, pillage and make a fuss.
Tip: Buy EVERY Bandit you can afford to.
Bribing armies is important too, i recommend bribing 3-5 times every army at your border so it will (probably) not follow the AI's orders.
For development i recommend building up support with the cheap (10-20 money) policies.Until you have consolidated your position long-term development is not advisable.

That is basically everything you need to know, now go out there and make Yuan Shikai proud!

I'll add tips on Characters, Diplomacy and Uprising Mechanics later.