Whoa. Alot of text. No time to read it all
This is one of the key features I would really like to see in mIRC.
I can imagine not wanting this in, has to do with some fixed principles about how an IRC client should behave. However, don't forget, it's about the goal, not the means.
I would say, don't underestimate the power of emoticons and the desire of people to use them. I hang out on forums alot and it really has added value in terms of giving the communication a bit more of depth.
I think having emoticons in can really boost the popularity of mIRC and increase the user base. This in combination with full scripts, who can make it more usuable. Right now people are using easy-to-use sites like Mibbit instead of mIRC, because it may seem to complex to use.
My two cents.