Planning for ASM

Hi, I'm looking for some recommendations on adding ASM to my environment. I currently have 4x nodes cluster (2x 4200 and 2x 5200).

 

What would be a good way to add ASM module? On all 4 devices ?

 

Is it OK to run ASM /w LTM on the same device? Or should I break the cluster into 2x 2-node clusters and run ASM on one cluster and LTM applications on another?

 

How much more load should I expect on devices /w ASM module?

 

From what I've read ASM module introduces policies which are assigned to a Standard VS /w HTTP profile...

 

How much maintenance does ASM require if enabled in transparent blocking mode using F5's signature database? How often does F5 update ASM signature database?

 

My thought was to enable ASM on 2x 5200 devices and group HTTP VSs on these two devices (I have multiple traffic groups to archive active/active cluster). What happens when traffic group / VS fails-over to one of 4200s without ASM module? Would VS stop processing traffic or would I simply loose ASM functions?

 

Thank you.