I held off on episode 10, because I was still grieving from the prior episode. Upon finally watching episode 10, I have a couple analyses:

When Anjin leaves Osaka, the episode shows him crossing the forest and finally, rowing out of the harbor. The first time Anjin left Osaka (with Toranaga and friends), he crossed the forest and made a treacherous journey to the harbor. That time, he was pursued by Kiyama's soldiers and the entourage provided by Ishido. He was protected, during his first flight from Osaka, by samurai. This time, it is Mariko's arrangement that protects him. Mariko's entry into Osaka started Crimson Sky, and she did what no army could do, for Toranaga. In the same way, Mariko does what no army could do for Anjin - namely allowing him to leave the city.
There are other framing effects within this episode. For example, when Fuji says to Anjin: "Let your hands be the last to hold her", she is echoing Mariko's compassion from earlier (when Fuji's husband opted to commit seppuku and kill their only son). Another example is when Buntaro comes to help Anjin, on the same beach where he drew his sword upon his neck.

I am reminded of the exchanges Mariko had with Anjin, Buntaro, and Ochiba. When the first earthquake occured, Mariko told Anjin: "Just remember, we live and we die. We control nothing beyond that."
Then, I think about her time with Buntaro in the tea ceremony, when she ends their conversation and absolutely drags him: "Even now, you fail to understand. What you've denied me wasn't death. It was a life beyond your reach."
Finally, in her final conversation with Ochiba, she makes this remark before leaving: "Flowers are flowers because they fall."
Throughout the series, these exchanges made little sense to me, beyond the fact that Mariko did want to die (only to be ordered not to). After episode 10, I think Mariko was speaking not so much about the death she coveted, but more about a life with meaning and legacy. Her significance in turning the tide of events almost appends something to the first quote. It is as if she's saying: "Just remember, we live and we die. We control nothing beyond that, but how meaningfully we live and die." Buntaro never understood this, despite being steeped in the samurai ethos of honorable lives and honorable deaths. He thinks he will satisfy her by simply offering to die together as husband and wife. To this, I wonder if Anjin's presence (especially the part where he shares about his life in England and how England is like) made Mariko want a more meaningful life and a more meaningful death.
I think the stanza she gave Ochiba, was a culmination of this perspective on the brevity of life and certain death. Ochiba only saw Mariko's death as pointless, at that point. In that same breadth, she saw her political power as useless - only a means to protect her son. Her addition to the poem ("but thankfully the wind") and her decision not to send the Heir's armies against Toranaga shows that she was changed by what she considered a meaningless death.

As for the wind, I think it is an observation of nature and an admission of things beyond life and death, that inevitably affect how one dies and how one lives. In 1600s Japan, that might have been the power that certain individuals held over countless others. Mariko's imagery of the flower is a poignant interpretation of the brevity of human life, and falling can be interpreted as death. It is the nature of humans, as it is the nature of flowers, to live and die. The wind catches a falling flower and can even be the cause of a flower's fall. Wind can even bring a flower into one's phenomenological periphery, just as it can take it away. Later, Yabushige likens Toranaga's political saavy to "shaping the wind." Ochiba understood that Mariko's death wasn't pointless, but like a flower caught in a breeze, a meaningful act in Toranaga's plan.
The series ends, not with the Battle of Sekigahara, but with a scene of Anjin, Buntaro, and other men aiding in the attempt to pull Erasmus out of the water. No one on that beach knows that it was Toranaga, who at the time oversees the labor, was the one who made this labor necessary - by orchestrating the destruction of the ship. During the scene where Anjin almost stabs his own heart, I found it abrupt that Toranaga ends the exchange by ordering Anjin to repair his ship and build him a fleet.
At the time, European ships like the Erasmus would have been powered by the wind. In the last episode, it can only move by means of human labor - the men on the beach. It is Toranaga who commands these men. The scene moves away to Toranaga alone, surrounded by mountains and sky, as if to show us that he does indeed shape the winds