Of course that, or something very close to it, is already possible with kwin. Reasonably current kwin is tiling capable, titlebar height (and lots more) is configurable, and as with any self-respecting kde app, all major triggerable functionality is mapped to configurable hotkeys.
FWIW, my kde is highly customized as a sort-of hybrid tiling/floating mixture, with floating dominating, but various windows configured to specific sizes and/or locations, including two dominant themes of maxed-Y/half-maxed-X for side-by-side for things like browsers and terminal windows, and maxed-X/almost-maxed-Y, lacking only titlebar height (and sometimes no-border so I get full app height as if it had the titlebar anyway), for things like tri-pane mail, news and feed-reader clients. Combined with (sloppy) focus follows mouse, click-to-raise and with semi-transparent inactive, that lets me work with either the two side-by-side windows or with the almost-maxed and a half-maxed window concurrently, or with all three windows, the back half-maxed one viewable when focused (but not raised) thru the semi-transparent inactive almost-maxed window above it.
It sounds horrible I know, but there's a productive workflow there that I've grown to depend on, and I was VERY unhappy when an earlier version of it broke with my transfer from kde3 to supposedly ready but still in reality VERY early alpha quality kde4. Fortunately I was able to work around or find alternate solutions for the broken bits, and kde4 itself has improved dramatically since then, such that at least with semantic-desktop not only turned off but actually compiled out (gentoo, USE=-semantic-desktop), I can honestly say I'm enjoying kde4 as much if not more than I did late kde3, now.