Planning local and online backups for a Hyper-V hosts environment

I'm trying to understand the Acronis methods of backup/restore, and plan for a scenario with local and online backups for a Hyper-V hosts environment.

Current environment:
* Four Hyper-V hosts (2008R2) with many VMs (all MS O/S) on each
* Each host has a local SAS-attached RAID array for backup using Windows Server Backup

We are considering moving from WSB to:
* Acronis Backup/Recovery, and
* Acronis Online, and
* Acronis Deduplication

Questions:
1) Can the backup RAID arrays remain locally attached to each host, or do they need to be consolidated as local devices on some "central" backup server? (The requirements for the "storage node"/"centralized vault"/deduplication setup has me a bit confused. And backing up to network shares just seems a bad idea.)
1a) If it has to be a centralized backup server, can that be one of the Hyper-V hosts or is that a bad idea?
2) In order to do both local and online backups, are the backups done twice (i.e., backup job to the local drive and then a separate backup job to the online storage)?
3) Will deduplication be applied to both the local and the online backups?
3a) Are these both source deduplications, target dedups, or some mix of both?
4) It appears that this will require one license of each product per host, correct?
5) Some hosts have over 1TB of space curently used, so 2TB per host for online backup may be insufficient. Can we incrementally increase the online backup quota per host beyond 2TB (at some fee, of course)?

Thanks