Complex configuration, any idea and help please.

Hi guys.
I must to do the below configuration on RouterOS
Firstly, I need to disuse with you for any idea or configuration.


A- ISP 1 connection must handle these traffic and priority order
Priority for traffic from/to interface WAN1 must be:
1-DNS
2-ICMP
3-VoIP (with IP 192.168.12.40)
4-HTTP
5-HTTPS
Where 1 is highest and 5 is lowest priority

While on other 2 ISP’s connections must handle all traffic (including HTTP traffic)
but respecting this priority order:
1-DNS, ICMP
2-HTTP
3-HTTPS
4-Messengers (msn, yahoo, skype, camfrog, irc, …)
5-game servers, Youtube and other video sites
6-windows Updates
7-other traffic
8-p2p traffic (bittorrent, utorrent, emule, limeware, bearshare etc…)
Where 1 is highest and 8 is lowest priority

B- If any of WAN connections will goes down,
predefined traffic from/to that interface must pas through to/from other WAN interfaces
till connection on disconnected WAN interface will be established.

C-May have one phisicual LAN interface with 2 subnets respecting these range of IPs:
Subnet1=192.168.12.0/24
Subnet2=192.168.11.0/24

D- Subnet1 (LAN A) must have higher priority than subnet2 (LAN B)

E- IP proxy cache on port 800, transparent proxy=yes, with drive2

F- Maximum possible speed of traffic from proxy cache to clients

Thnk you for your help!
3 interfaces to Internet.jpg

Please, any suggestion regarding only point A?

Thank you in advance.