At Whom Were the Plagues and the Sea Splitting Directed?

The following are questions and source texts to help answer them, from the Torah, Midrash and commentaries.

What did the splitting of the Sea accomplish?

What was the purpose of the plagues? 

"I will send my hand and smite Egypt... and then he will send you......"
"Let my people go to worship me, and you have refused, I will kill your firstborn."
"I will take you to me as a people and I will be to you as G-d, and you will know that I the L-rd your G-d take you out of Egypt......"
"I will give my hand in Egypt, and I will take... my people Israel out with great signs. Egypt will know that I am G-d when I place my hand on Egypt....."
( Moses to Pharaoh): "With this you will know that I am G-d...so that you will know that no one is like our G-d....."
"So that you should know that I am the L-rd in the midst of the land....
This is why I have kept you, in order to show you My glory and so that you should tell of my Name in all the earth.  So that you should know that to the L-rd is the land."
"I have hardened his heart... in order that I can place the signs in his midst. And in order for you to tell in the ears of your son and your grandson what I have done in Egypt and you will know that I am the L-rd.  (the Egyptian first born will die, and the Israelites will not die- ) so that you (Pharaoh) should know that the L-rd distinguishes between Egypt and Israel."
"They should be a sign on your arm and a remembrance between your eyes that with a strong hand the L-d took you out of Egypt."

What was the Israelite reaction to Moshe and G-d's promises?
(after Moshe initially shows the people the staff/ snake, leprosy miracles): "The people believed and they heard that the L-rd redeemed Israel, and they knelt and bowed."
(initially) "They did not listen to Moshe out of shortness of breath and hard work."
(before the 10th plague, hearing of future Passovers in Israel:) "The people knelt and bowed."

What was their reaction to the plagues?
(after Pharaoh increased their workload in response to Moshe's request):
"May the L-d look at you and judge that you have spoiled our spirits in the  eyes of Pharaoh... to give a sword in his hands to kill us."
(after 9 plagues:) "Moshe was great in the land of Egypt, in the eyes of Pharaoh's servants and in the eyes of the people." (Ibn Ezra- Egypt. Ramban- Israel.)
(after being told to offer the paschal sacrifice): "The children of Israel went and did as the L-rd commanded Moshe and Aharon."

Were they active in their redemption?
G-d: "Each woman should ask from her neighbor for silver and gold vessels and dresses."
"Moshe was very great in the eyes of the servants of Pharaoh and the people."
Ibn Ezra- Egypt. Nachmanides- Israel.
"the blood shall be a sign"
"you shall eat in haste."
"armed did the children of Israel go up out of Egypt"
"The children of Israel went out with a strong hand, brazenly"

Was Israel active or passive at the splitting of the sea?
They called out to the L-rd
Israel: are there no graves in Egypt..
Moshe: stand and see the salvation of G-d
G-d: speak to the children of Israel and let them travel and the children of Israel will go in the sea on the dry land
Midrash- a) you jump, no you. b) I'll jump, I'll jump- Nachshon- I'll jump.
"Moshe raised his hands on the sea.."
"they believed in the L-d and in Moshe His servant"
"then sang Moshe and the children of Israel.."
"Miriam took the drum and the women followed with drums and dances"
Midrash: What a handmaid saw at the Sea was greater than what Ezekiel the prophet saw.

 What was the purpose of the splitting of the sea?
"Pharaoh will chase you... and Egypt will know that I am the L-rd"
"Israel lifted its eyes and Egypt was traveling behind them."
Moshe: "See the great salvation which the L-d will do for you today, for as you saw Egypt today you will never see them again forever."
G-d: "Egypt will know that I am the L-rd"
Egypt: "I will run away from Israel for G-d fights for them in Egypt."
(after the Egyptians drowned:) "The people believed in the L-d and in Moshe His servant."
in the song: "the nations heard, they trembled"