This worries me. The "usability" folks are at the plate again, wanting to "simplify" things.
Just so you know, I regularly and routinely use advanced features in KDE. I have at least a dozen applications with very specifically configured window positions and decoration settings. The panel is carefully configured to behave how I need it; grouping control and changing the order of applications manually is absolutely essential. I routinely change pager options to suit my current needs at any moment. I have customized the crap out of key maps, file associations, Konsole, Dolphin and Kate.
Notice how I make zero mention of "activities," nepomuk, baloo or akonadi.
If you need to hide some of the "advanced" features behind an "advanced" button to satisfy your notion of aesthetics then that's fine. Two things: 1.) Do. Not. Remove. Features. 2.) Once I've enabled "advanced" features somewhere don't make me do it again.
That way the added burden I face is hitting each "advanced" button once, and only once, and never thinking about it again.
Done right I can imagine a gentle reorganization of configuration being a small benefit to KDE. If you indulge configuration hating zealots that remove capabilities and dumb down KDE you will breed an army of haters. You will live in a world of haters hating on your work for the rest of your adult life.
Keep that in mind as you "simplify."