Proxmox Cluster in OVH, can my planned infrastructure work like this?

Hello everybody, my client asked me to design a clustered environment, but i'm tight to OVH

i have choose 2 EG server, from enterprise category, so i have vRack 1.5. i'm planning to have a two nodes cluster, with DRBD over the second 10GBs nic through vRack 1.5, in combination with OVH IP failover 9,90€/month offer instead of fencing and HA. So my question are:

1. will vrack 1.5 allow me to setup a cluster using multicast? do i need to do any tweaking or forcing unicast?
2. will DRBD over my internal 10gb nic will work? (ovh nas solution are terrible slow).
3. i'm planning to deploy 4 containers (1 x firewall, 1 x webserver, 1 x mysql, 1 x webapp cache) : in a cluster situation (it means i have a go for points 1 and 2) will i be able to use let's say webserver on cluster1 and mysql on cluster2? will this brake clustering? in case of cluster1 node failure will i be able to run my vm only from cluster2?

i really really apreciate any kind of help since googling for proxmox, ovh, vrack and clustering all toghether did not brings are results in the last 4 hours :)

again thank you
Simone