You're off to a good start.
Redundancy
- Active/Active on your iSCSI Multipathing configuration.
- I would use two NICs for Management/VMotion traffic (assuming you won't be doing alot of load balancing). One plugged into the first switch and the other plugged into the other switch. At least the same for VM and iSCSI (more on this below).
- Performance
- Less vSwitches. More NIC teaming. More vSwitches do not improve performance.
- Separating your iSCSI subnet twice doesn't provide any performance advantage. I assume you have a sepeate VM subnet (this simply makes it clearer to analyze/debug as your traffic is isolated).
- Ensure you're running at full duplex everywhere.
- How many NIC connections are you using for your VM networks? How you divvy it up between VM, iSCSI, management is based on your application profile (e.g. backend intensive or front end intensive).
- Use a spearate iSCSI target per LUN to separate your queues. Make sure you use Round Robin in the multipathing configuration (default).
- RAID level on your filer matters.
Maximum performance depends on your application(s) use case. You'll want to monitor the traffic across your VMKernel ports and your VM network to ensure you're providing . Enable DRS.
1. We're getting there.
2. No
3. Depends on your work load.
4. See above.