Why does it say "Asher Lo ha'Yam"?
Radak: After mentioning the land in general, now it details the sea and land. It is all Lo - b'Yado and in His Reshus.
Malbim: [The nations think that] also the sea is due to purely to Hashem (people's actions do not affect it). After the initial creation, He told the water to gathered, and there was sea and dry land.
Why does it say "v'Hu Asahu"?
Radak: He prepared it, that the water will gather to one place.
What is the meaning of "v'Yabeshes Yadav Yatzaru"?
Radak: He formed the dry land so living beings and vegetation will live on it. Since all is in His hand, above and below, He can raise and lower whom He wants. He put us lowly in this long Galus, and now He lifted us over all nations!