«3: having the maximization effect specific windows, instead of all of them or none of them.»
This is not *quickly* and *easily* doable.
mIRC is implemented as a MDI (Multiple Document Interface... or something like that). The window around, with the menu bar, the tool bar and the switch bar, is the parent window. The others are child windows. Each child has some properties, some are common to all child windows, others are specific to one of them. The property that specifies if windows are maximized or of normal size is common to all of them. That is, if one window is maximized, they are all maximized. If one is of normal size... got it?
There might be possibilities of simulating windows through other means/methods, but that would be re-coding Windows. A goal of Windows is for it to provide a lot of tool programs can use, so they don't need to do them again and can concentrate on doing something usefull. Programers follow the rule "Don't re-invente the wheel", therefore no programer (except a very crazy one) would rewrite everything (build a new window-like system) for so little change (allow maximized and normal-size windows within a MDI application).
One solution I see, if someone here is a crazy programer, is to use panels place on the parent window, catch click so that I can get one panel over another, get resized, etc, and place other components on it and draw a title bar... Please contact me if you implement my idea, I wan't to see it :P