No, the CPU cannot be upgraded. Cisco has replaced the 4210 model with the 4215, which is also targetted towards lower bandwidth networks, but provides a little more processor power. You can upgrade the RAM in the 4210 to 512 MB (in fact it is required to run the CIDS 4.1(1) and later relases).
You can get performance metrics from the sensor using the show interface command. It will provide you with most of the information you have requested. Also from IDM you can request statistics from the monitoring page.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...