3) Add -w to /cnick ( w = aways)
I believe this has been suggested before and the problem that arises is that mIRC would have to /whois someone (or something similar) to find out if their away. This would lag you quite a lot if you're in several channels, especially several
big channels.
I believe you can find scripted alternatives.
4) I think /describe could support more than one "thing". Example: /describe #help,#usa say Hello to everybody
I don't know if depends on the server you're using, but it already does. I tested this on DALnet/Undernet/EFnet and it worked. You do not see both the actions get sent to both channels though, it appears:
-> *#arnie1,#arnie2* testRegards,