Signed with a kiss

I never quite know what the etiquette is with regard to signing emails, text messages, Facebook posts and so forth with 'x'.  I've noticed since I moved here that the British seem to be much more free and easy with their 'x's than we emotionally-stunted Irish, who tend to view the insertion of an 'x' at the end of a message as a proposal of marriage, procreation and eventual amalgamation of livestock herds.  I've been trying to infer a system of rules for the beleaguered Paddy.  Here is my preliminary attempt:

1. Only insert an 'x' at the end of an email to a peer.  It doesn't tend to go down well with one's elders, in particular one's superiors.
2. Two 'x's is okay; three is also commonplace.  More than that is possible, but looks a little desperate.
3. The insertion of an 'x' at the end of a message does not signal romantic intent, unless it occurs in violation of rule (1).  Exercise caution.
3a. Furthermore, the use of an 'x' doesn't even necessarily mean you like the person all that much.  So, if you're surprised by the insertion of an 'x' at the end of a message from an unlikely party, scan the message for veiled attempts to get you to do something for the author.  Resist said attempts, even if they are from an attractive member of the opposite sex.  Skepticism is key here.
3b. Irish men, be aware that sometimes British men sign messages to each other with 'x's.  (Not only that, but heterosexual British men do on occasion hug and kiss each other IN REAL LIFE.  Imagine that.)  If you receive such a message, remember: it doesn't mean that the author wants to proposition you.  Resist the urge to break out the holy water and the SuperSoaker.
4. Capitals or lowercase, it's really a matter of personal taste.  Don't waste time trying to make them into little fences, like XxXxX.  This is just silly.

I will update this list as required as I progress through the uncharted waters of British communication etiquette.  Watch this space.