ike2: SAi1 in msg 3

["jpickering%creeksidenet.com" <jpickering@xxxxxxxxxxxxxxxx>]

In Ike2, section 3.1 for msg 3 the text reads:

The initial payloads in message three are identical to the payloads in 
message 1.

While this may be true for payload types, it is clearly not required for 
payload
contents since the key may differ if Bob chooses a proposal that changes the
DH group. This brings up the question of  the contents of SAi1 in message 3:
Should this payload contain the original proposal set or the single 
proposal chosen
by Bob? And what should Bob do when receiving the payload?

Another question regards Bob's nonce contents in message 2: if Bob places
state information in message 2, eg. which suite he chose, what is the 
advantage
of encrypting this state if Bob's cookie effectively signs the nonce?

Always grateful for helpful clarification.

Jeff