All I can say is; what the heck are you talking about?
What problem is solved?
Did you read any of it or did you just skim over parts and guess as to what was going on and though "I'll answer this part this way"?
While I have no qualms with what you're suggesting, I'll go ahead and explain what RoCK said.
If mirc.ini is in the same folder as mirc.exe, then it'll use the mirc.ini in that folder, instead of the one from the appdata folder.
If you didn't understand what I said, here's a little more clarification:
By having mirc.ini in the same dir as mirc.exe (C:\mIRC\ or C:\Program Files\mIRC\) you can use the normal .\download directory, instead of the one in the appdir.
In case you missed it when you installed your new version of mIRC, mIRC lets you install it over your old installations. Because of this, it's considered an mIRC "Upgrade" and it will keep your "original" mirc.ini file.
(meaning, when you update, it doesn't just push everything to the appdirs)