#3, #4, and #5 really shouldn't be an issue. A reverse DNS lookup (or IPBlock) on a user's IP address (when they are suspected of multiaccounting) will generally yield a domain name which, with a little bit of common sense, someone at Evony should be able to determine is a site where multiple players would log in from (university, Panara Bread, other wifi hot-spots, etc.)
Now, on the other hand, doing the same thing, and yielding information which would indicate it is not a wifi hot spot (i.e. an cable ISP IP address) would suggest multiaccounting...
In those instances, I believe Evony should email all the email addresses which log in from such addresses and point out that multiaccounting is "against the rules"...
When I last examined the Terms of Service a month or so ago, the Terms of Service did not state having multiple accounts was against the TOS. Some mods attempted to state that "rules" posted in these forums were an "extension" of the TOS, but Section 20 of the TOS is pretty explicit that the TOS is the solely binding legal agreement between the parties, and as such, a forum post saying multi-accounts are against the rules is pretty much a moot point.

