I concur.
I should state that the dockable channel bar as shown in that image, should still not take away from the channel info dialog.
That is still an important function of mIRC.
As you suggested, it would be best if the dockable info bar was perhaps an additional method of quickly changing topics/modes for that particular channel.
I very much agree with your suggestions.
Perhaps even going further to make each channel bar so that you can put your most used items for a particular channel in that bar. And as you switch windows, it would then update the bar with the relevant information.
Thanks for your input