First off, apologies for ranting about the Castilians and Chagatai. I haven't seen maps of the Empire in a while.
While I also support expansion into Eastern Asia, I must say that we should be careful with our actions taken there. Taking Ming ports would not be a good idea. Although we would gain footholds in the East and potentially gain new resources, we would have to spend many more resources managing the new colonies. The Chinese do not take kindly to being under foreign rule, and it would take ages to educate all of them in Roman ways and effectively assimilate them into the Empire. If Your Highness still wishes to invade China, though, I recommend going after the gold mines of Caozhou.
That being said, we should seize the Russian possessions in the Pacific, especially Taiwan and the Philippines. They would weaken our enemy and also serve the same purpose as footholds in China, only easier to manage and without Chinese cores to provoke the Celestial Empire.
Perhaps we could seek out a trading agreement or an alliance with the Celestial Empire? The original Empire under the Caesars established friendly trading relations with the Han Empire thousands of years ago. They would be a useful ally against the Russians, and if we help them to "westernize," a Sino-Roman alliance will be unstoppable. That is just my opinion though, Basilissa. The choice is yours.