If you have defined th policy then you would use "propsals" if you use "proposal-set" then you ould use one of the predefined system proposal set
# set security ipsec policy ipsec-pol proposal-set ?
Possible completions:
basic (IPSEC basic proposal-set)
compatible (IPSEC compatible proposal-set)
standard (IPSEC standard proposal-set)
suiteb-gcm-128 (IPSec proposal-set for Suite-B-GCM-128)
suiteb-gcm-256 (IPSec proposal-set for Suite-B-GCM-256)
I have4 not looked at the rest of the config
Look at this Juniper example:
First define the parameters of the proposal named "ipsec-phase2-proposal" (this is the user defined proposal 
set security ipsec proposal ipsec-phase2-proposal protocol esp
set security ipsec proposal ipsec-phase2-proposal authentication-algorithm hmac-sha1-96
set security ipsec proposal ipsec-phase2-proposal encryption-algorithm aes-128-cbc
Now you define the policy named " ipsec-phase2-policy" and reference the proposal "ipsec-phase2-proposal" that was just defined
set security ipsec policy ipsec-phase2-policy proposals ipsec-phase2-proposal
Add some mre security if defined on the other end
set security ipsec policy ipsec-phase2-policy perfect-forward-secrecy keys group2