SRX 1500 and EX 2300 virtaul chassis and Etherchannel

Dear all,

I would like to know design confusion for virtual chassis and ehterchannel.

Please see the below diagram and help me. According to https://kb.juniper.net/InfoCenter/index?page=content&id=KB22474

1. Juniper recommand Design one,correct ?
2. Let me know my cable connectivity is correct or not ?
3. Let me know weight mornigoring need to configure all interface ge-0/0/0,g0/0/1,g-7/0/0,ge-7/0/0/1 ?

   Eg:

   (set chassis cluster redundancy-group 1 interface-monitor ge-0/0/0 weight 255
   set chassis cluster redundancy-group 1 interface-monitor ge-0/0/1 weight 255
   set chassis cluster redundancy-group 1 interface-monitor ge-7/0/0 weight 255
   set chassis cluster redundancy-group 1 interface-monitor ge-7/0/1 weight 255)

4. if i didn't add interface mornitoring,what is disadvantage ?
5. May i know pros and cons for  lacp periodic slow or fast ?
6. in juniper etherchannel can support fail-over link ? I mean i don't want Traffic loadbalace  adn  i want to use 1 cable of Ex2300 is primary and second link is backup , juniper support ?
7. If we didn't use etherchannel ,can i use trunk only ?