What is the connection between the good and the bad?
Malbim: Just like Hashgachah brought everything good upon you when you served Hashem, it will bring all bad on you if you transgress His Bris.
What is Oschem?
Radak: It is Eschem. We find a Cholem like this (in place of a Segol) elsewhere
Why does it say "Ka'asher Ba
Malbim: The good comes automatically; Hashem's decree is final. Evil is always conditional; if they will repent, it will not be carried out.