[abind]

I do this with XFCE and it works really well. You just have to prevent xfce-panel and xfwm from starting up and autostart i3 instead. Replacing i3 with xfwm on the fly also works like a charm, I can toggle between tiling and floating WM's using keyboard shortcuts.

[stormbrew]

When I try to use xfce components they interfere a lot with keyboard shortcuts. I'm not sure why, but most of the gtk-compatible DEs bundle keyboard shortcut stuff with the settings-daemon, which is really the piece I miss most. It just leaves things feeling more broken to me, but maybe I'm doing something wrong.

[abind]

I generally add custom application shortcuts to XFCE's keyboard preferences instead of i3's config and change i3's $mod to the Alt key. Haven't had any problems of conflicting shortcuts.